{ "content": [ { "type": "text", "text": "# systemd.network (info)\n\n## NAME\n\nsystemd.network - Network configuration\n\n## SYNOPSIS\n\nnetwork.network\n\n## DESCRIPTION\n\nA plain ini-style text file that encodes network configuration for\nmatching network interfaces, used by systemd-networkd(8). See\nsystemd.syntax(7) for a general description of the syntax.\n\n## Sections\n\n- **NAME**\n- **SYNOPSIS**\n- **DESCRIPTION**\n- **EXAMPLES**\n- **SEE ALSO**\n- **NOTES**\n\nUse structuredContent.sections for detailed options, examples, and full documentation.\n" } ], "structuredContent": { "command": "systemd.network", "section": "", "mode": "info", "summary": "systemd.network - Network configuration", "synopsis": "network.network", "tldr_summary": null, "tldr_examples": [], "tldr_source": null, "flags": [], "examples": [ "Example 1. Static network configuration", "# /etc/systemd/network/50-static.network", "[Match]", "Name=enp2s0", "[Network]", "Address=192.168.0.15/24", "Gateway=192.168.0.1", "This brings interface \"enp2s0\" up with a static address. The specified", "gateway will be used for a default route.", "Example 2. DHCP on ethernet links", "# /etc/systemd/network/80-dhcp.network", "[Match]", "Name=en*", "[Network]", "DHCP=yes", "This will enable DHCPv4 and DHCPv6 on all interfaces with names", "starting with \"en\" (i.e. ethernet interfaces).", "Example 3. IPv6 Prefix Delegation", "# /etc/systemd/network/55-ipv6-pd-upstream.network", "[Match]", "Name=enp1s0", "[Network]", "DHCP=ipv6", "# /etc/systemd/network/56-ipv6-pd-downstream.network", "[Match]", "Name=enp2s0", "[Network]", "IPv6SendRA=yes", "DHCPv6PrefixDelegation=yes", "This will enable DHCPv6-PD on the interface enp1s0 as an upstream", "interface where the DHCPv6 client is running and enp2s0 as a downstream", "interface where the prefix is delegated to. The delegated prefixes are", "distributed by IPv6 Router Advertisement on the downstream network.", "Example 4. A bridge with two enslaved links", "# /etc/systemd/network/25-bridge-static.network", "[Match]", "Name=bridge0", "[Network]", "Address=192.168.0.15/24", "Gateway=192.168.0.1", "DNS=192.168.0.1", "# /etc/systemd/network/25-bridge-slave-interface-1.network", "[Match]", "Name=enp2s0", "[Network]", "Bridge=bridge0", "# /etc/systemd/network/25-bridge-slave-interface-2.network", "[Match]", "Name=wlp3s0", "[Network]", "Bridge=bridge0", "This creates a bridge and attaches devices \"enp2s0\" and \"wlp3s0\" to it.", "The bridge will have the specified static address and network assigned,", "and a default route via the specified gateway will be added. The", "specified DNS server will be added to the global list of DNS resolvers.", "Example 5. Bridge port with VLAN forwarding", "# /etc/systemd/network/25-bridge-slave-interface-1.network", "[Match]", "Name=enp2s0", "[Network]", "Bridge=bridge0", "[BridgeVLAN]", "VLAN=1-32", "PVID=42", "EgressUntagged=42", "[BridgeVLAN]", "VLAN=100-200", "[BridgeVLAN]", "EgressUntagged=300-400", "This overrides the configuration specified in the previous example for", "the interface \"enp2s0\", and enables VLAN on that bridge port. VLAN IDs", "1-32, 42, 100-400 will be allowed. Packets tagged with VLAN IDs 42,", "300-400 will be untagged when they leave on this interface. Untagged", "packets which arrive on this interface will be assigned VLAN ID 42.", "Example 6. Various tunnels", "/etc/systemd/network/25-tunnels.network", "[Match]", "Name=ens1", "[Network]", "Tunnel=ipip-tun", "Tunnel=sit-tun", "Tunnel=gre-tun", "Tunnel=vti-tun", "/etc/systemd/network/25-tunnel-ipip.netdev", "[NetDev]", "Name=ipip-tun", "Kind=ipip", "/etc/systemd/network/25-tunnel-sit.netdev", "[NetDev]", "Name=sit-tun", "Kind=sit", "/etc/systemd/network/25-tunnel-gre.netdev", "[NetDev]", "Name=gre-tun", "Kind=gre", "/etc/systemd/network/25-tunnel-vti.netdev", "[NetDev]", "Name=vti-tun", "Kind=vti", "This will bring interface \"ens1\" up and create an IPIP tunnel, a SIT", "tunnel, a GRE tunnel, and a VTI tunnel using it.", "Example 7. A bond device", "# /etc/systemd/network/30-bond1.network", "[Match]", "Name=bond1", "[Network]", "DHCP=ipv6", "# /etc/systemd/network/30-bond1.netdev", "[NetDev]", "Name=bond1", "Kind=bond", "# /etc/systemd/network/30-bond1-dev1.network", "[Match]", "MACAddress=52:54:00:e9:64:41", "[Network]", "Bond=bond1", "# /etc/systemd/network/30-bond1-dev2.network", "[Match]", "MACAddress=52:54:00:e9:64:42", "[Network]", "Bond=bond1", "This will create a bond device \"bond1\" and enslave the two devices with", "MAC addresses 52:54:00:e9:64:41 and 52:54:00:e9:64:42 to it. IPv6 DHCP", "will be used to acquire an address.", "Example 8. Virtual Routing and Forwarding (VRF)", "Add the \"bond1\" interface to the VRF master interface \"vrf1\". This will", "redirect routes generated on this interface to be within the routing", "table defined during VRF creation. For kernels before 4.8 traffic won't", "be redirected towards the VRFs routing table unless specific ip-rules", "are added.", "# /etc/systemd/network/25-vrf.network", "[Match]", "Name=bond1", "[Network]", "VRF=vrf1", "Example 9. MacVTap", "This brings up a network interface \"macvtap-test\" and attaches it to", "\"enp0s25\".", "# /lib/systemd/network/25-macvtap.network", "[Match]", "Name=enp0s25", "[Network]", "MACVTAP=macvtap-test", "Example 10. A Xfrm interface with physical underlying device.", "# /etc/systemd/network/27-xfrm.netdev", "[NetDev]", "Name=xfrm0", "Kind=xfrm", "[Xfrm]", "InterfaceId=7", "# /etc/systemd/network/27-eth0.network", "[Match]", "Name=eth0", "[Network]", "Xfrm=xfrm0", "This creates a \"xfrm0\" interface and binds it to the \"eth0\" device.", "This allows hardware based ipsec offloading to the \"eth0\" nic. If", "offloading is not needed, xfrm interfaces can be assigned to the \"lo\"", "device." ], "see_also": [ { "name": "systemd", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/systemd/1/json" }, { "name": "systemd-networkd.service", "section": "8", "url": "https://www.chedong.com/phpMan.php/man/systemd-networkd.service/8/json" }, { "name": "systemd.link", "section": "5", "url": "https://www.chedong.com/phpMan.php/man/systemd.link/5/json" }, { "name": "systemd.netdev", "section": "5", "url": "https://www.chedong.com/phpMan.php/man/systemd.netdev/5/json" }, { "name": "systemd-resolved.service", "section": "8", "url": "https://www.chedong.com/phpMan.php/man/systemd-resolved.service/8/json" } ], "section_outline": [ { "name": "NAME", "lines": 2, "subsections": [] }, { "name": "SYNOPSIS", "lines": 2, "subsections": [] }, { "name": "DESCRIPTION", "lines": 2928, "subsections": [] }, { "name": "EXAMPLES", "lines": 219, "subsections": [] }, { "name": "SEE ALSO", "lines": 3, "subsections": [] }, { "name": "NOTES", "lines": 70, "subsections": [] } ], "sections": { "NAME": { "content": "systemd.network - Network configuration\n", "subsections": [] }, "SYNOPSIS": { "content": "network.network\n", "subsections": [] }, "DESCRIPTION": { "content": "A plain ini-style text file that encodes network configuration for\nmatching network interfaces, used by systemd-networkd(8). See\nsystemd.syntax(7) for a general description of the syntax.\n\nThe main network file must have the extension .network; other\nextensions are ignored. Networks are applied to links whenever the\nlinks appear.\n\nThe .network files are read from the files located in the system\nnetwork directories /lib/systemd/network and\n/usr/local/lib/systemd/network, the volatile runtime network directory\n/run/systemd/network and the local administration network directory\n/etc/systemd/network. All configuration files are collectively sorted\nand processed in lexical order, regardless of the directories in which\nthey live. However, files with identical filenames replace each other.\nFiles in /etc/ have the highest priority, files in /run/ take\nprecedence over files with the same name under /usr/. This can be used\nto override a system-supplied configuration file with a local file if\nneeded. As a special case, an empty file (file size 0) or symlink with\nthe same name pointing to /dev/null disables the configuration file\nentirely (it is \"masked\").\n\nAlong with the network file foo.network, a \"drop-in\" directory\nfoo.network.d/ may exist. All files with the suffix \".conf\" from this\ndirectory will be merged in the alphanumeric order and parsed after the\nmain file itself has been parsed. This is useful to alter or add\nconfiguration settings, without having to modify the main configuration\nfile. Each drop-in file must have appropriate section headers.\n\nIn addition to /etc/systemd/network, drop-in \".d\" directories can be\nplaced in /lib/systemd/network or /run/systemd/network directories.\nDrop-in files in /etc/ take precedence over those in /run/ which in\nturn take precedence over those in /lib/. Drop-in files under any of\nthese directories take precedence over the main network file wherever\nlocated.\n\n[MATCH] SECTION OPTIONS\nThe network file contains a [Match] section, which determines if a\ngiven network file may be applied to a given device; and a [Network]\nsection specifying how the device should be configured. The first (in\nlexical order) of the network files that matches a given device is\napplied, all later files are ignored, even if they match as well.\n\nNote that any network interfaces that have the IDNETMANAGEDBY= udev\nproperty set will never be matched by any .network files - unless the\nproperty's value is the string \"io.systemd.Network\" - even if the\n[Match] section would otherwise match. This may be used to exclude\nspecific network interfaces from systemd-networkd's management, while\nkeeping the [Match] section generic. The IDNETMANAGEDBY= poperty\nthus declares intended ownership of the device, and permits ensuring\nthat concurrent network management implementations do not compete for\nmanagement of specific devices.\n\nA network file is said to match a network interface if all matches\nspecified by the [Match] section are satisfied. When a network file\ndoes not contain valid settings in [Match] section, then the file will\nmatch all interfaces and systemd-networkd warns about that. Hint: to\navoid the warning and to make it clear that all interfaces shall be\nmatched, add the following:\n\nName=*\n\nThe following keys are accepted:\n\nMACAddress=\nA whitespace-separated list of hardware addresses. Use full colon-,\nhyphen- or dot-delimited hexadecimal. See the example below. This\noption may appear more than once, in which case the lists are\nmerged. If the empty string is assigned to this option, the list of\nhardware addresses defined prior to this is reset.\n\nExample:\n\nMACAddress=01:23:45:67:89:ab 00-11-22-33-44-55 AABB.CCDD.EEFF\n\nPermanentMACAddress=\nA whitespace-separated list of hardware's permanent addresses.\nWhile MACAddress= matches the device's current MAC address, this\nmatches the device's permanent MAC address, which may be different\nfrom the current one. Use full colon-, hyphen- or dot-delimited\nhexadecimal. This option may appear more than once, in which case\nthe lists are merged. If the empty string is assigned to this\noption, the list of hardware addresses defined prior to this is\nreset.\n\nPath=\nA whitespace-separated list of shell-style globs matching the\npersistent path, as exposed by the udev property IDPATH.\n\nDriver=\nA whitespace-separated list of shell-style globs matching the\ndriver currently bound to the device, as exposed by the udev\nproperty IDNETDRIVER of its parent device, or if that is not set,\nthe driver as exposed by ethtool -i of the device itself. If the\nlist is prefixed with a \"!\", the test is inverted.\n\nType=\nA whitespace-separated list of shell-style globs matching the\ndevice type, as exposed by networkctl list. If the list is prefixed\nwith a \"!\", the test is inverted. Some valid values are \"ether\",\n\"loopback\", \"wlan\", \"wwan\". Valid types are named either from the\nudev \"DEVTYPE\" attribute, or \"ARPHRD\" macros in linux/ifarp.h, so\nthis is not comprehensive.\n\nProperty=\nA whitespace-separated list of udev property names with their\nvalues after equals sign (\"=\"). If multiple properties are\nspecified, the test results are ANDed. If the list is prefixed with\na \"!\", the test is inverted. If a value contains white spaces, then\nplease quote whole key and value pair. If a value contains\nquotation, then please escape the quotation with \"\\\".\n\nExample: if a .link file has the following:\n\nProperty=IDMODELID=9999 \"IDVENDORFROMDATABASE=vendor name\" \"KEY=with \\\"quotation\\\"\"\n\nthen, the .link file matches only when an interface has all the\nabove three properties.\n\nName=\nA whitespace-separated list of shell-style globs matching the\ndevice name, as exposed by the udev property \"INTERFACE\", or\ndevice's alternative names. If the list is prefixed with a \"!\", the\ntest is inverted.\n\nWLANInterfaceType=\nA whitespace-separated list of wireless network type. Supported\nvalues are \"ad-hoc\", \"station\", \"ap\", \"ap-vlan\", \"wds\", \"monitor\",\n\"mesh-point\", \"p2p-client\", \"p2p-go\", \"p2p-device\", \"ocb\", and\n\"nan\". If the list is prefixed with a \"!\", the test is inverted.\n\nSSID=\nA whitespace-separated list of shell-style globs matching the SSID\nof the currently connected wireless LAN. If the list is prefixed\nwith a \"!\", the test is inverted.\n\nBSSID=\nA whitespace-separated list of hardware address of the currently\nconnected wireless LAN. Use full colon-, hyphen- or dot-delimited\nhexadecimal. See the example in MACAddress=. This option may appear\nmore than once, in which case the lists are merged. If the empty\nstring is assigned to this option, the list is reset.\n\nHost=\nMatches against the hostname or machine ID of the host. See\nConditionHost= in systemd.unit(5) for details. When prefixed with\nan exclamation mark (\"!\"), the result is negated. If an empty\nstring is assigned, then previously assigned value is cleared.\n\nVirtualization=\nChecks whether the system is executed in a virtualized environment\nand optionally test whether it is a specific implementation. See\nConditionVirtualization= in systemd.unit(5) for details. When\nprefixed with an exclamation mark (\"!\"), the result is negated. If\nan empty string is assigned, then previously assigned value is\ncleared.\n\nKernelCommandLine=\nChecks whether a specific kernel command line option is set. See\nConditionKernelCommandLine= in systemd.unit(5) for details. When\nprefixed with an exclamation mark (\"!\"), the result is negated. If\nan empty string is assigned, then previously assigned value is\ncleared.\n\nKernelVersion=\nChecks whether the kernel version (as reported by uname -r) matches\na certain expression. See ConditionKernelVersion= in\nsystemd.unit(5) for details. When prefixed with an exclamation mark\n(\"!\"), the result is negated. If an empty string is assigned, then\npreviously assigned value is cleared.\n\nArchitecture=\nChecks whether the system is running on a specific architecture.\nSee ConditionArchitecture= in systemd.unit(5) for details. When\nprefixed with an exclamation mark (\"!\"), the result is negated. If\nan empty string is assigned, then previously assigned value is\ncleared.\n\nFirmware=\nChecks whether the system is running on a machine with the\nspecified firmware. See ConditionFirmware= in systemd.unit(5) for\ndetails. When prefixed with an exclamation mark (\"!\"), the result\nis negated. If an empty string is assigned, then previously\nassigned value is cleared.\n\n[LINK] SECTION OPTIONS\nThe [Link] section accepts the following keys:\n\nMACAddress=\nThe hardware address to set for the device.\n\nMTUBytes=\nThe maximum transmission unit in bytes to set for the device. The\nusual suffixes K, M, G, are supported and are understood to the\nbase of 1024.\n\nNote that if IPv6 is enabled on the interface, and the MTU is\nchosen below 1280 (the minimum MTU for IPv6) it will automatically\nbe increased to this value.\n\nARP=\nTakes a boolean. If set to true, the ARP (low-level Address\nResolution Protocol) for this interface is enabled. When unset, the\nkernel's default will be used.\n\nFor example, disabling ARP is useful when creating multiple MACVLAN\nor VLAN virtual interfaces atop a single lower-level physical\ninterface, which will then only serve as a link/\"bridge\" device\naggregating traffic to the same physical link and not participate\nin the network otherwise. Defaults to unset.\n\nMulticast=\nTakes a boolean. If set to true, the multicast flag on the device\nis enabled. Defaults to unset.\n\nAllMulticast=\nTakes a boolean. If set to true, the driver retrieves all multicast\npackets from the network. This happens when multicast routing is\nenabled. Defaults to unset.\n\nPromiscuous=\nTakes a boolean. If set to true, promiscuous mode of the interface\nis enabled. Defaults to unset.\n\nUnmanaged=\nTakes a boolean. When \"yes\", no attempts are made to bring up or\nconfigure matching links, equivalent to when there are no matching\nnetwork files. Defaults to \"no\".\n\nThis is useful for preventing later matching network files from\ninterfering with certain interfaces that are fully controlled by\nother applications.\n\nGroup=\nLink groups are similar to port ranges found in managed switches.\nWhen network interfaces are added to a numbered group, operations\non all the interfaces from that group can be performed at once.\nTakes an unsigned integer in the range 0...4294967295. Defaults to\nunset.\n\nRequiredForOnline=\nTakes a boolean or a minimum operational state and an optional\nmaximum operational state. Please see networkctl(1) for possible\noperational states. When \"yes\", the network is deemed required when\ndetermining whether the system is online (including when running\nsystemd-networkd-wait-online). When \"no\", the network is ignored\nwhen determining the online state. When a minimum operational state\nand an optional maximum operational state are set, \"yes\" is\nimplied, and this controls the minimum and maximum operational\nstate required for the network interface to be considered online.\n\nDefaults to \"yes\" when ActivationPolicy= is not set, or set to\n\"up\", \"always-up\", or \"bound\". Defaults to \"no\" when\nActivationPolicy= is set to \"manual\" or \"down\". This is forced to\n\"no\" when ActivationPolicy= is set to \"always-down\".\n\nThe network will be brought up normally (as configured by\nActivationPolicy=), but in the event that there is no address being\nassigned by DHCP or the cable is not plugged in, the link will\nsimply remain offline and be skipped automatically by\nsystemd-networkd-wait-online if \"RequiredForOnline=no\".\n\nRequiredFamilyForOnline=\nTakes an address family. When specified, an IP address in the given\nfamily is deemed required when determining whether the link is\nonline (including when running systemd-networkd-wait-online). Takes\none of \"ipv4\", \"ipv6\", \"both\", or \"any\". Defaults to \"any\". Note\nthat this option has no effect if \"RequiredForOnline=no\", or if\n\"RequiredForOnline=\" specifies a minimum operational state below\n\"degraded\".\n\nActivationPolicy=\nSpecifies the policy for systemd-networkd managing the link\nadministrative state. Specifically, this controls how\nsystemd-networkd changes the network device's \"IFFUP\" flag, which\nis sometimes controlled by system administrators by running e.g.,\nip link set dev eth0 up or ip link set dev eth0 down, and can also\nbe changed with networkctl up eth0 or networkctl down eth0.\n\nTakes one of \"up\", \"always-up\", \"manual\", \"always-down\", \"down\", or\n\"bound\". When \"manual\", systemd-networkd will not change the link's\nadmin state automatically; the system administrator must bring the\ninterface up or down manually, as desired. When \"up\" (the default)\nor \"always-up\", or \"down\" or \"always-down\", systemd-networkd will\nset the link up or down, respectively, when the interface is\n(re)configured. When \"always-up\" or \"always-down\", systemd-networkd\nwill set the link up or down, respectively, any time\nsystemd-networkd detects a change in the administrative state. When\nBindCarrier= is also set, this is automatically set to \"bound\" and\nany other value is ignored.\n\nWhen the policy is set to \"down\" or \"manual\", the default value of\nRequiredForOnline= is \"no\". When the policy is set to\n\"always-down\", the value of RequiredForOnline= forced to \"no\".\n\nThe administrative state is not the same as the carrier state, so\nusing \"always-up\" does not mean the link will never lose carrier.\nThe link carrier depends on both the administrative state as well\nas the network device's physical connection. However, to avoid\nreconfiguration failures, when using \"always-up\",\nIgnoreCarrierLoss= is forced to true.\n\n[SR-IOV] SECTION OPTIONS\nThe [SR-IOV] section accepts the following keys. Specify several\n[SR-IOV] sections to configure several SR-IOVs. SR-IOV provides the\nability to partition a single physical PCI resource into virtual PCI\nfunctions which can then be injected into a VM. In the case of network\nVFs, SR-IOV improves north-south network performance (that is, traffic\nwith endpoints outside the host machine) by allowing traffic to bypass\nthe host machine's network stack.\n\nVirtualFunction=\nSpecifies a Virtual Function (VF), lightweight PCIe function\ndesigned solely to move data in and out. Takes an unsigned integer\nin the range 0...2147483646. This option is compulsory.\n\nVLANId=\nSpecifies VLAN ID of the virtual function. Takes an unsigned\ninteger in the range 1...4095.\n\nQualityOfService=\nSpecifies quality of service of the virtual function. Takes an\nunsigned integer in the range 1...4294967294.\n\nVLANProtocol=\nSpecifies VLAN protocol of the virtual function. Takes \"802.1Q\" or\n\"802.1ad\".\n\nMACSpoofCheck=\nTakes a boolean. Controls the MAC spoof checking. When unset, the\nkernel's default will be used.\n\nQueryReceiveSideScaling=\nTakes a boolean. Toggle the ability of querying the receive side\nscaling (RSS) configuration of the virtual function (VF). The VF\nRSS information like RSS hash key may be considered sensitive on\nsome devices where this information is shared between VF and the\nphysical function (PF). When unset, the kernel's default will be\nused.\n\nTrust=\nTakes a boolean. Allows to set trust mode of the virtual function\n(VF). When set, VF users can set a specific feature which may\nimpact security and/or performance. When unset, the kernel's\ndefault will be used.\n\nLinkState=\nAllows to set the link state of the virtual function (VF). Takes a\nboolean or a special value \"auto\". Setting to \"auto\" means a\nreflection of the physical function (PF) link state, \"yes\" lets the\nVF to communicate with other VFs on this host even if the PF link\nstate is down, \"no\" causes the hardware to drop any packets sent by\nthe VF. When unset, the kernel's default will be used.\n\nMACAddress=\nSpecifies the MAC address for the virtual function.\n\n[NETWORK] SECTION OPTIONS\nThe [Network] section accepts the following keys:\n\nDescription=\nA description of the device. This is only used for presentation\npurposes.\n\nDHCP=\nEnables DHCPv4 and/or DHCPv6 client support. Accepts \"yes\", \"no\",\n\"ipv4\", or \"ipv6\". Defaults to \"no\".\n\nNote that DHCPv6 will by default be triggered by Router\nAdvertisement, if that is enabled, regardless of this parameter. By\nenabling DHCPv6 support explicitly, the DHCPv6 client will be\nstarted regardless of the presence of routers on the link, or what\nflags the routers pass. See \"IPv6AcceptRA=\".\n\nFurthermore, note that by default the domain name specified through\nDHCP, on Ubuntu, are used for name resolution. See option\nUseDomains= below.\n\nSee the [DHCPv4] or [DHCPv6] sections below for further\nconfiguration options for the DHCP client support.\n\nDHCPServer=\nTakes a boolean. If set to \"yes\", DHCPv4 server will be started.\nDefaults to \"no\". Further settings for the DHCP server may be set\nin the [DHCPServer] section described below.\n\nLinkLocalAddressing=\nEnables link-local address autoconfiguration. Accepts yes, no,\nipv4, and ipv6. An IPv6 link-local address is configured when yes\nor ipv6. An IPv4 link-local address is configured when yes or ipv4\nand when DHCPv4 autoconfiguration has been unsuccessful for some\ntime. (IPv4 link-local address autoconfiguration will usually\nhappen in parallel with repeated attempts to acquire a DHCPv4\nlease).\n\nDefaults to no when Bridge=yes is set, and ipv6 otherwise.\n\nIPv6LinkLocalAddressGenerationMode=\nSpecifies how IPv6 link local address is generated. Takes one of\n\"eui64\", \"none\", \"stable-privacy\" and \"random\". When unset,\n\"stable-privacy\" is used if IPv6StableSecretAddress= is specified,\nand if not, \"eui64\" is used. Note that if LinkLocalAddressing= is\n\"no\" or \"ipv4\", then IPv6LinkLocalAddressGenerationMode= will be\nignored. Also, even if LinkLocalAddressing= is \"yes\" or \"ipv6\",\nsetting IPv6LinkLocalAddressGenerationMode=none disables to\nconfigure an IPv6 link-local address.\n\nIPv6StableSecretAddress=\nTakes an IPv6 address. The specified address will be used as a\nstable secret for generating IPv6 link-local address. If this\nsetting is specified, and IPv6LinkLocalAddressGenerationMode= is\nunset, then IPv6LinkLocalAddressGenerationMode=stable-privacy is\nimplied. If this setting is not specified, and \"stable-privacy\" is\nset to IPv6LinkLocalAddressGenerationMode=, then a stable secret\naddress will be generated from the local machine ID and the\ninterface name.\n\nIPv4LLRoute=\nTakes a boolean. If set to true, sets up the route needed for\nnon-IPv4LL hosts to communicate with IPv4LL-only hosts. Defaults to\nfalse.\n\nDefaultRouteOnDevice=\nTakes a boolean. If set to true, sets up the default route bound to\nthe interface. Defaults to false. This is useful when creating\nroutes on point-to-point interfaces. This is equivalent to e.g. the\nfollowing,\n\nip route add default dev veth99\n\nor,\n\n[Route]\nGateway=0.0.0.0\n\nCurrently, there are no way to specify e.g., the table for the\nroute configured by this setting. To configure the default route\nwith such an additional property, please use the following instead:\n\n[Route]\nGateway=0.0.0.0\nTable=1234\n\nIPv6Token=\nSpecifies an optional address generation mode for the Stateless\nAddress Autoconfiguration (SLAAC). Supported modes are\n\"prefixstable\" and \"static\".\n\nWhen the mode is set to \"static\", an IPv6 address must be specified\nafter a colon (\":\"), and the lower bits of the supplied address are\ncombined with the upper bits of a prefix received in a Router\nAdvertisement (RA) message to form a complete address. Note that if\nmultiple prefixes are received in an RA message, or in multiple RA\nmessages, addresses will be formed from each of them using the\nsupplied address. This mode implements SLAAC but uses a static\ninterface identifier instead of an identifier generated by using\nthe EUI-64 algorithm. Because the interface identifier is static,\nif Duplicate Address Detection detects that the computed address is\na duplicate (in use by another node on the link), then this mode\nwill fail to provide an address for that prefix. If an IPv6 address\nwithout mode is specified, then \"static\" mode is assumed.\n\nWhen the mode is set to \"prefixstable\" the RFC 7217[1] algorithm\nfor generating interface identifiers will be used. This mode can\noptionally take an IPv6 address separated with a colon (\":\"). If an\nIPv6 address is specified, then an interface identifier is\ngenerated only when a prefix received in an RA message matches the\nsupplied address.\n\nIf no address generation mode is specified (which is the default),\nor a received prefix does not match any of the addresses provided\nin \"prefixstable\" mode, then the EUI-64 algorithm will be used to\nform an interface identifier for that prefix. This mode is also\nSLAAC, but with a potentially stable interface identifier which\ndoes not directly map to the interface's hardware address.\n\nNote that the \"prefixstable\" algorithm uses both the interface name\nand MAC address as input to the hash to compute the interface\nidentifier, so if either of those are changed the resulting\ninterface identifier (and address) will change, even if the prefix\nreceived in the RA message has not changed.\n\nThis setting can be specified multiple times. If an empty string is\nassigned, then the all previous assignments are cleared.\n\nExamples:\n\nIPv6Token=::1a:2b:3c:4d\nIPv6Token=static:::1a:2b:3c:4d\nIPv6Token=prefixstable\nIPv6Token=prefixstable:2002:da8:1::\n\nLLMNR=\nTakes a boolean or \"resolve\". When true, enables Link-Local\nMulticast Name Resolution[2] on the link. When set to \"resolve\",\nonly resolution is enabled, but not host registration and\nannouncement. Defaults to true. This setting is read by systemd-\nresolved.service(8).\n\nMulticastDNS=\nTakes a boolean or \"resolve\". When true, enables Multicast DNS[3]\nsupport on the link. When set to \"resolve\", only resolution is\nenabled, but not host or service registration and announcement.\nDefaults to false. This setting is read by systemd-\nresolved.service(8).\n\nDNSOverTLS=\nTakes a boolean or \"opportunistic\". When true, enables\nDNS-over-TLS[4] support on the link. When set to \"opportunistic\",\ncompatibility with non-DNS-over-TLS servers is increased, by\nautomatically turning off DNS-over-TLS servers in this case. This\noption defines a per-interface setting for resolved.conf(5)'s\nglobal DNSOverTLS= option. Defaults to false. This setting is read\nby systemd-resolved.service(8).\n\nDNSSEC=\nTakes a boolean or \"allow-downgrade\". When true, enables DNSSEC[5]\nDNS validation support on the link. When set to \"allow-downgrade\",\ncompatibility with non-DNSSEC capable networks is increased, by\nautomatically turning off DNSSEC in this case. This option defines\na per-interface setting for resolved.conf(5)'s global DNSSEC=\noption. Defaults to false. This setting is read by systemd-\nresolved.service(8).\n\nDNSSECNegativeTrustAnchors=\nA space-separated list of DNSSEC negative trust anchor domains. If\nspecified and DNSSEC is enabled, look-ups done via the interface's\nDNS server will be subject to the list of negative trust anchors,\nand not require authentication for the specified domains, or\nanything below it. Use this to disable DNSSEC authentication for\nspecific private domains, that cannot be proven valid using the\nInternet DNS hierarchy. Defaults to the empty list. This setting is\nread by systemd-resolved.service(8).\n\nLLDP=\nControls support for Ethernet LLDP packet reception. LLDP is a\nlink-layer protocol commonly implemented on professional routers\nand bridges which announces which physical port a system is\nconnected to, as well as other related data. Accepts a boolean or\nthe special value \"routers-only\". When true, incoming LLDP packets\nare accepted and a database of all LLDP neighbors maintained. If\n\"routers-only\" is set only LLDP data of various types of routers is\ncollected and LLDP data about other types of devices ignored (such\nas stations, telephones and others). If false, LLDP reception is\ndisabled. Defaults to \"routers-only\". Use networkctl(1) to query\nthe collected neighbor data. LLDP is only available on Ethernet\nlinks. See EmitLLDP= below for enabling LLDP packet emission from\nthe local system.\n\nEmitLLDP=\nControls support for Ethernet LLDP packet emission. Accepts a\nboolean parameter or the special values \"nearest-bridge\",\n\"non-tpmr-bridge\" and \"customer-bridge\". Defaults to false, which\nturns off LLDP packet emission. If not false, a short LLDP packet\nwith information about the local system is sent out in regular\nintervals on the link. The LLDP packet will contain information\nabout the local hostname, the local machine ID (as stored in\nmachine-id(5)) and the local interface name, as well as the pretty\nhostname of the system (as set in machine-info(5)). LLDP emission\nis only available on Ethernet links. Note that this setting passes\ndata suitable for identification of host to the network and should\nthus not be enabled on untrusted networks, where such\nidentification data should not be made available. Use this option\nto permit other systems to identify on which interfaces they are\nconnected to this system. The three special values control\npropagation of the LLDP packets. The \"nearest-bridge\" setting\npermits propagation only to the nearest connected bridge,\n\"non-tpmr-bridge\" permits propagation across Two-Port MAC Relays,\nbut not any other bridges, and \"customer-bridge\" permits\npropagation until a customer bridge is reached. For details about\nthese concepts, see IEEE 802.1AB-2016[6]. Note that configuring\nthis setting to true is equivalent to \"nearest-bridge\", the\nrecommended and most restricted level of propagation. See LLDP=\nabove for an option to enable LLDP reception.\n\nBindCarrier=\nA link name or a list of link names. When set, controls the\nbehavior of the current link. When all links in the list are in an\noperational down state, the current link is brought down. When at\nleast one link has carrier, the current interface is brought up.\n\nThis forces ActivationPolicy= to be set to \"bound\".\n\nAddress=\nA static IPv4 or IPv6 address and its prefix length, separated by a\n\"/\" character. Specify this key more than once to configure several\naddresses. The format of the address must be as described in\ninetpton(3). This is a short-hand for an [Address] section only\ncontaining an Address key (see below). This option may be specified\nmore than once.\n\nIf the specified address is \"0.0.0.0\" (for IPv4) or \"::\" (for\nIPv6), a new address range of the requested size is automatically\nallocated from a system-wide pool of unused ranges. Note that the\nprefix length must be equal or larger than 8 for IPv4, and 64 for\nIPv6. The allocated range is checked against all current network\ninterfaces and all known network configuration files to avoid\naddress range conflicts. The default system-wide pool consists of\n192.168.0.0/16, 172.16.0.0/12 and 10.0.0.0/8 for IPv4, and fd00::/8\nfor IPv6. This functionality is useful to manage a large number of\ndynamically created network interfaces with the same network\nconfiguration and automatic address range assignment.\n\nGateway=\nThe gateway address, which must be in the format described in\ninetpton(3). This is a short-hand for a [Route] section only\ncontaining a Gateway key. This option may be specified more than\nonce.\n\nDNS=\nA DNS server address, which must be in the format described in\ninetpton(3). This option may be specified more than once. Each\naddress can optionally take a port number separated with \":\", a\nnetwork interface name or index separated with \"%\", and a Server\nName Indication (SNI) separated with \"#\". When IPv6 address is\nspecified with a port number, then the address must be in the\nsquare brackets. That is, the acceptable full formats are\n\"111.222.333.444:9953%ifname#example.com\" for IPv4 and\n\"[1111:2222::3333]:9953%ifname#example.com\" for IPv6. If an empty\nstring is assigned, then the all previous assignments are cleared.\nThis setting is read by systemd-resolved.service(8).\n\nDomains=\nA whitespace-separated list of domains which should be resolved\nusing the DNS servers on this link. Each item in the list should be\na domain name, optionally prefixed with a tilde (\"~\"). The domains\nwith the prefix are called \"routing-only domains\". The domains\nwithout the prefix are called \"search domains\" and are first used\nas search suffixes for extending single-label hostnames (hostnames\ncontaining no dots) to become fully qualified domain names (FQDNs).\nIf a single-label hostname is resolved on this interface, each of\nthe specified search domains are appended to it in turn, converting\nit into a fully qualified domain name, until one of them may be\nsuccessfully resolved.\n\nBoth \"search\" and \"routing-only\" domains are used for routing of\nDNS queries: look-ups for hostnames ending in those domains (hence\nalso single label names, if any \"search domains\" are listed), are\nrouted to the DNS servers configured for this interface. The domain\nrouting logic is particularly useful on multi-homed hosts with DNS\nservers serving particular private DNS zones on each interface.\n\nThe \"routing-only\" domain \"~.\" (the tilde indicating definition of\na routing domain, the dot referring to the DNS root domain which is\nthe implied suffix of all valid DNS names) has special effect. It\ncauses all DNS traffic which does not match another configured\ndomain routing entry to be routed to DNS servers specified for this\ninterface. This setting is useful to prefer a certain set of DNS\nservers if a link on which they are connected is available.\n\nThis setting is read by systemd-resolved.service(8). \"Search\ndomains\" correspond to the domain and search entries in\nresolv.conf(5). Domain name routing has no equivalent in the\ntraditional glibc API, which has no concept of domain name servers\nlimited to a specific link.\n\nDNSDefaultRoute=\nTakes a boolean argument. If true, this link's configured DNS\nservers are used for resolving domain names that do not match any\nlink's configured Domains= setting. If false, this link's\nconfigured DNS servers are never used for such domains, and are\nexclusively used for resolving names that match at least one of the\ndomains configured on this link. If not specified defaults to an\nautomatic mode: queries not matching any link's configured domains\nwill be routed to this link if it has no routing-only domains\nconfigured.\n\nNTP=\nAn NTP server address (either an IP address, or a hostname). This\noption may be specified more than once. This setting is read by\nsystemd-timesyncd.service(8).\n\nIPForward=\nConfigures IP packet forwarding for the system. If enabled,\nincoming packets on any network interface will be forwarded to any\nother interfaces according to the routing table. Takes a boolean,\nor the values \"ipv4\" or \"ipv6\", which only enable IP packet\nforwarding for the specified address family. This controls the\nnet.ipv4.ipforward and net.ipv6.conf.all.forwarding sysctl options\nof the network interface (see ip-sysctl.txt[7] for details about\nsysctl options). Defaults to \"no\".\n\nNote: this setting controls a global kernel option, and does so one\nway only: if a network that has this setting enabled is set up the\nglobal setting is turned on. However, it is never turned off again,\neven after all networks with this setting enabled are shut down\nagain.\n\nTo allow IP packet forwarding only between specific network\ninterfaces use a firewall.\n\nIPMasquerade=\nConfigures IP masquerading for the network interface. If enabled,\npackets forwarded from the network interface will be appear as\ncoming from the local host. Takes one of \"ipv4\", \"ipv6\", \"both\", or\n\"no\". Defaults to \"no\". If enabled, this automatically sets\nIPForward= to one of \"ipv4\", \"ipv6\" or \"yes\".\n\nNote. Any positive boolean values such as \"yes\" or \"true\" are now\ndeprecated. Please use one of the values in the above.\n\nIPv6PrivacyExtensions=\nConfigures use of stateless temporary addresses that change over\ntime (see RFC 4941[8], Privacy Extensions for Stateless Address\nAutoconfiguration in IPv6). Takes a boolean or the special values\n\"prefer-public\" and \"kernel\". When true, enables the privacy\nextensions and prefers temporary addresses over public addresses.\nWhen \"prefer-public\", enables the privacy extensions, but prefers\npublic addresses over temporary addresses. When false, the privacy\nextensions remain disabled. When \"kernel\", the kernel's default\nsetting will be left in place. Defaults to \"no\".\n\nIPv6AcceptRA=\nTakes a boolean. Controls IPv6 Router Advertisement (RA) reception\nsupport for the interface. If true, RAs are accepted; if false, RAs\nare ignored. When RAs are accepted, they may trigger the start of\nthe DHCPv6 client if the relevant flags are set in the RA data, or\nif no routers are found on the link. The default is to disable RA\nreception for bridge devices or when IP forwarding is enabled, and\nto enable it otherwise. Cannot be enabled on bond devices and when\nlink local addressing is disabled.\n\nFurther settings for the IPv6 RA support may be configured in the\n[IPv6AcceptRA] section, see below.\n\nAlso see ip-sysctl.txt[7] in the kernel documentation regarding\n\"acceptra\", but note that systemd's setting of 1 (i.e. true)\ncorresponds to kernel's setting of 2.\n\nNote that kernel's implementation of the IPv6 RA protocol is always\ndisabled, regardless of this setting. If this option is enabled, a\nuserspace implementation of the IPv6 RA protocol is used, and the\nkernel's own implementation remains disabled, since\nsystemd-networkd needs to know all details supplied in the\nadvertisements, and these are not available from the kernel if the\nkernel's own implementation is used.\n\nIPv6DuplicateAddressDetection=\nConfigures the amount of IPv6 Duplicate Address Detection (DAD)\nprobes to send. When unset, the kernel's default will be used.\n\nIPv6HopLimit=\nConfigures IPv6 Hop Limit. For each router that forwards the\npacket, the hop limit is decremented by 1. When the hop limit field\nreaches zero, the packet is discarded. When unset, the kernel's\ndefault will be used.\n\nIPv4AcceptLocal=\nTakes a boolean. Accept packets with local source addresses. In\ncombination with suitable routing, this can be used to direct\npackets between two local interfaces over the wire and have them\naccepted properly. When unset, the kernel's default will be used.\n\nIPv4RouteLocalnet=\nTakes a boolean. When true, the kernel does not consider loopback\naddresses as martian source or destination while routing. This\nenables the use of 127.0.0.0/8 for local routing purposes. When\nunset, the kernel's default will be used.\n\nIPv4ProxyARP=\nTakes a boolean. Configures proxy ARP for IPv4. Proxy ARP is the\ntechnique in which one host, usually a router, answers ARP requests\nintended for another machine. By \"faking\" its identity, the router\naccepts responsibility for routing packets to the \"real\"\ndestination. See RFC 1027[9]. When unset, the kernel's default will\nbe used.\n\nIPv6ProxyNDP=\nTakes a boolean. Configures proxy NDP for IPv6. Proxy NDP (Neighbor\nDiscovery Protocol) is a technique for IPv6 to allow routing of\naddresses to a different destination when peers expect them to be\npresent on a certain physical link. In this case a router answers\nNeighbour Advertisement messages intended for another machine by\noffering its own MAC address as destination. Unlike proxy ARP for\nIPv4, it is not enabled globally, but will only send Neighbour\nAdvertisement messages for addresses in the IPv6 neighbor proxy\ntable, which can also be shown by ip -6 neighbour show proxy.\nsystemd-networkd will control the per-interface `proxyndp` switch\nfor each configured interface depending on this option. When unset,\nthe kernel's default will be used.\n\nIPv6ProxyNDPAddress=\nAn IPv6 address, for which Neighbour Advertisement messages will be\nproxied. This option may be specified more than once.\nsystemd-networkd will add the IPv6ProxyNDPAddress= entries to the\nkernel's IPv6 neighbor proxy table. This option implies\nIPv6ProxyNDP=yes but has no effect if IPv6ProxyNDP has been set to\nfalse. When unset, the kernel's default will be used.\n\nIPv6SendRA=\nWhether to enable or disable Router Advertisement sending on a\nlink. Takes a boolean value. When enabled, prefixes configured in\n[IPv6Prefix] sections and routes configured in [IPv6RoutePrefix]\nsections are distributed as defined in the [IPv6SendRA] section. If\nDHCPv6PrefixDelegation= is enabled, then the delegated prefixes are\nalso distributed. See DHCPv6PrefixDelegation= setting and the\n[IPv6SendRA], [IPv6Prefix], [IPv6RoutePrefix], and\n[DHCPv6PrefixDelegation] sections for more configuration options.\n\nDHCPv6PrefixDelegation=\nTakes a boolean value. When enabled, requests prefixes using a\nDHCPv6 client configured on another link. By default, an address\nwithin each delegated prefix will be assigned, and the prefixes\nwill be announced through IPv6 Router Advertisement when\nIPv6SendRA= is enabled. Such default settings can be configured in\n[DHCPv6PrefixDelegation] section. Defaults to disabled.\n\nIPv6MTUBytes=\nConfigures IPv6 maximum transmission unit (MTU). An integer greater\nthan or equal to 1280 bytes. When unset, the kernel's default will\nbe used.\n\nBatmanAdvanced=, Bond=, Bridge=, VRF=\nThe name of the B.A.T.M.A.N. Advanced, bond, bridge, or VRF\ninterface to add the link to. See systemd.netdev(5).\n\nIPVLAN=, IPVTAP=, L2TP=, MACsec=, MACVLAN=, MACVTAP=, Tunnel=, VLAN=,\nVXLAN=, Xfrm=\nThe name of an IPVLAN, IPVTAP, L2TP, MACsec, MACVLAN, MACVTAP,\ntunnel, VLAN, VXLAN, or Xfrm to be created on the link. See\nsystemd.netdev(5). This option may be specified more than once.\n\nActiveSlave=\nTakes a boolean. Specifies the new active slave. The \"ActiveSlave=\"\noption is only valid for following modes: \"active-backup\",\n\"balance-alb\" and \"balance-tlb\". Defaults to false.\n\nPrimarySlave=\nTakes a boolean. Specifies which slave is the primary device. The\nspecified device will always be the active slave while it is\navailable. Only when the primary is off-line will alternate devices\nbe used. This is useful when one slave is preferred over another,\ne.g. when one slave has higher throughput than another. The\n\"PrimarySlave=\" option is only valid for following modes:\n\"active-backup\", \"balance-alb\" and \"balance-tlb\". Defaults to\nfalse.\n\nConfigureWithoutCarrier=\nTakes a boolean. Allows networkd to configure a specific link even\nif it has no carrier. Defaults to false. If IgnoreCarrierLoss= is\nnot explicitly set, it will default to this value.\n\nIgnoreCarrierLoss=\nTakes a boolean. Allows networkd to retain both the static and\ndynamic configuration of the interface even if its carrier is lost.\nWhen unset, the value specified with ConfigureWithoutCarrier= is\nused.\n\nWhen ActivationPolicy= is set to \"always-up\", this is forced to\n\"true\".\n\nKeepConfiguration=\nTakes a boolean or one of \"static\", \"dhcp-on-stop\", \"dhcp\". When\n\"static\", systemd-networkd will not drop static addresses and\nroutes on starting up process. When set to \"dhcp-on-stop\",\nsystemd-networkd will not drop addresses and routes on stopping the\ndaemon. When \"dhcp\", the addresses and routes provided by a DHCP\nserver will never be dropped even if the DHCP lease expires. This\nis contrary to the DHCP specification, but may be the best choice\nif, e.g., the root filesystem relies on this connection. The\nsetting \"dhcp\" implies \"dhcp-on-stop\", and \"yes\" implies \"dhcp\" and\n\"static\". Defaults to \"no\".\n\n[ADDRESS] SECTION OPTIONS\nAn [Address] section accepts the following keys. Specify several\n[Address] sections to configure several addresses.\n\nAddress=\nAs in the [Network] section. This key is mandatory. Each [Address]\nsection can contain one Address= setting.\n\nPeer=\nThe peer address in a point-to-point connection. Accepts the same\nformat as the Address= key.\n\nBroadcast=\nTakes an IPv4 address or boolean value. The address must be in the\nformat described in inetpton(3). If set to true, then the IPv4\nbroadcast address will be derived from the Address= setting. If set\nto false, then the broadcast address will not be set. Defaults to\ntrue, except for wireguard interfaces, where it default to false.\n\nLabel=\nAn address label.\n\nPreferredLifetime=\nAllows the default \"preferred lifetime\" of the address to be\noverridden. Only three settings are accepted: \"forever\",\n\"infinity\", which is the default and means that the address never\nexpires, and \"0\", which means that the address is considered\nimmediately \"expired\" and will not be used, unless explicitly\nrequested. A setting of PreferredLifetime=0 is useful for addresses\nwhich are added to be used only by a specific application, which is\nthen configured to use them explicitly.\n\nScope=\nThe scope of the address, which can be \"global\" (valid everywhere\non the network, even through a gateway), \"link\" (only valid on this\ndevice, will not traverse a gateway) or \"host\" (only valid within\nthe device itself, e.g. 127.0.0.1) or an unsigned integer in the\nrange 0...255. Defaults to \"global\".\n\nRouteMetric=\nThe metric of the prefix route, which is pointing to the subnet of\nthe configured IP address, taking the configured prefix length into\naccount. Takes an unsigned integer in the range 0...4294967295.\nWhen unset or set to 0, the kernel's default value is used. This\nsetting will be ignored when AddPrefixRoute= is false.\n\nHomeAddress=\nTakes a boolean. Designates this address the \"home address\" as\ndefined in RFC 6275[10]. Supported only on IPv6. Defaults to false.\n\nDuplicateAddressDetection=\nTakes one of \"ipv4\", \"ipv6\", \"both\", \"none\". When \"ipv4\", performs\nIPv4 Address Conflict Detection. See RFC 5227[11]. When \"ipv6\",\nperforms IPv6 Duplicate Address Detection. See RFC 4862[12].\nDefaults to \"ipv4\" for IPv4 link-local addresses, \"ipv6\" for IPv6\naddresses, and \"none\" otherwise.\n\nManageTemporaryAddress=\nTakes a boolean. If true the kernel manage temporary addresses\ncreated from this one as template on behalf of Privacy Extensions\nRFC 3041[13]. For this to become active, the usetempaddr sysctl\nsetting has to be set to a value greater than zero. The given\naddress needs to have a prefix length of 64. This flag allows using\nprivacy extensions in a manually configured network, just like if\nstateless auto-configuration was active. Defaults to false.\n\nAddPrefixRoute=\nTakes a boolean. When true, the prefix route for the address is\nautomatically added. Defaults to true.\n\nAutoJoin=\nTakes a boolean. Joining multicast group on ethernet level via ip\nmaddr command would not work if we have an Ethernet switch that\ndoes IGMP snooping since the switch would not replicate multicast\npackets on ports that did not have IGMP reports for the multicast\naddresses. Linux vxlan interfaces created via ip link add vxlan or\nnetworkd's netdev kind vxlan have the group option that enables\nthen to do the required join. By extending ip address command with\noption \"autojoin\" we can get similar functionality for openvswitch\n(OVS) vxlan interfaces as well as other tunneling mechanisms that\nneed to receive multicast traffic. Defaults to \"no\".\n\n[NEIGHBOR] SECTION OPTIONS\nA [Neighbor] section accepts the following keys. The neighbor section\nadds a permanent, static entry to the neighbor table (IPv6) or ARP\ntable (IPv4) for the given hardware address on the links matched for\nthe network. Specify several [Neighbor] sections to configure several\nstatic neighbors.\n\nAddress=\nThe IP address of the neighbor.\n\nLinkLayerAddress=\nThe link layer address (MAC address or IP address) of the neighbor.\n\n[IPV6ADDRESSLABEL] SECTION OPTIONS\nAn [IPv6AddressLabel] section accepts the following keys. Specify\nseveral [IPv6AddressLabel] sections to configure several address\nlabels. IPv6 address labels are used for address selection. See RFC\n3484[14]. Precedence is managed by userspace, and only the label itself\nis stored in the kernel.\n\nLabel=\nThe label for the prefix, an unsigned integer in the range\n0-4294967294. 0xffffffff is reserved. This setting is mandatory.\n\nPrefix=\nIPv6 prefix is an address with a prefix length, separated by a\nslash \"/\" character. This key is mandatory.\n\n[ROUTINGPOLICYRULE] SECTION OPTIONS\nAn [RoutingPolicyRule] section accepts the following keys. Specify\nseveral [RoutingPolicyRule] sections to configure several rules.\n\nTypeOfService=\nTakes a number between 0 and 255 that specifies the type of service\nto match.\n\nFrom=\nSpecifies the source address prefix to match. Possibly followed by\na slash and the prefix length.\n\nTo=\nSpecifies the destination address prefix to match. Possibly\nfollowed by a slash and the prefix length.\n\nFirewallMark=\nSpecifies the iptables firewall mark value to match (a number\nbetween 1 and 4294967295). Optionally, the firewall mask (also a\nnumber between 1 and 4294967295) can be suffixed with a slash\n(\"/\"), e.g., \"7/255\".\n\nTable=\nSpecifies the routing table identifier to lookup if the rule\nselector matches. Takes one of predefined names \"default\", \"main\",\nand \"local\", and names defined in RouteTable= in networkd.conf(5),\nor a number between 1 and 4294967295. Defaults to \"main\".\n\nPriority=\nSpecifies the priority of this rule. Priority= is an unsigned\ninteger in the range 0...4294967295. Higher number means lower\npriority, and rules get processed in order of increasing number.\nDefaults to unset, and the kernel will pick a value dynamically.\n\nIncomingInterface=\nSpecifies incoming device to match. If the interface is loopback,\nthe rule only matches packets originating from this host.\n\nOutgoingInterface=\nSpecifies the outgoing device to match. The outgoing interface is\nonly available for packets originating from local sockets that are\nbound to a device.\n\nSourcePort=\nSpecifies the source IP port or IP port range match in forwarding\ninformation base (FIB) rules. A port range is specified by the\nlower and upper port separated by a dash. Defaults to unset.\n\nDestinationPort=\nSpecifies the destination IP port or IP port range match in\nforwarding information base (FIB) rules. A port range is specified\nby the lower and upper port separated by a dash. Defaults to unset.\n\nIPProtocol=\nSpecifies the IP protocol to match in forwarding information base\n(FIB) rules. Takes IP protocol name such as \"tcp\", \"udp\" or \"sctp\",\nor IP protocol number such as \"6\" for \"tcp\" or \"17\" for \"udp\".\nDefaults to unset.\n\nInvertRule=\nA boolean. Specifies whether the rule is to be inverted. Defaults\nto false.\n\nFamily=\nTakes a special value \"ipv4\", \"ipv6\", or \"both\". By default, the\naddress family is determined by the address specified in To= or\nFrom=. If neither To= nor From= are specified, then defaults to\n\"ipv4\".\n\nUser=\nTakes a username, a user ID, or a range of user IDs separated by a\ndash. Defaults to unset.\n\nSuppressPrefixLength=\nTakes a number N in the range 0...128 and rejects routing decisions\nthat have a prefix length of N or less. Defaults to unset.\n\nType=\nSpecifies Routing Policy Database (RPDB) rule type. Takes one of\n\"blackhole\", \"unreachable\" or \"prohibit\".\n\n[NEXTHOP] SECTION OPTIONS\nThe [NextHop] section is used to manipulate entries in the kernel's\n\"nexthop\" tables. The [NextHop] section accepts the following keys.\nSpecify several [NextHop] sections to configure several hops.\n\nId=\nThe id of the next hop. Takes an unsigned integer in the range\n1...4294967295. If left unspecified, then automatically chosen by\nkernel.\n\nGateway=\nAs in the [Network] section.\n\nFamily=\nTakes one of the special values \"ipv4\" or \"ipv6\". By default, the\nfamily is determined by the address specified in Gateway=. If\nGateway= is not specified, then defaults to \"ipv4\".\n\nOnLink=\nTakes a boolean. If set to true, the kernel does not have to check\nif the gateway is reachable directly by the current machine (i.e.,\nattached to the local network), so that we can insert the nexthop\nin the kernel table without it being complained about. Defaults to\n\"no\".\n\nBlackhole=\nTakes a boolean. If enabled, packets to the corresponding routes\nare discarded silently, and Gateway= cannot be specified. Defaults\nto \"no\".\n\nGroup=\nTakes a whitespace separated list of nexthop IDs. Each ID must be\nin the range 1...4294967295. Optionally, each nexthop ID can take a\nweight after a colon (\"id[:weight]\"). The weight must be in the\nrange 1...255. If the weight is not specified, then it is assumed\nthat the weight is 1. This setting cannot be specified with\nGateway=, Family=, Blackhole=. This setting can be specified\nmultiple times. If an empty string is assigned, then the all\nprevious assignments are cleared. Defaults to unset.\n\n[ROUTE] SECTION OPTIONS\nThe [Route] section accepts the following keys. Specify several [Route]\nsections to configure several routes.\n\nGateway=\nTakes the gateway address or the special values \"dhcp4\" and\n\"ipv6ra\". If \"dhcp4\" or \"ipv6ra\" is set, then the gateway\naddress provided by DHCPv4 or IPv6 RA is used.\n\nGatewayOnLink=\nTakes a boolean. If set to true, the kernel does not have to check\nif the gateway is reachable directly by the current machine (i.e.,\nattached to the local network), so that we can insert the route in\nthe kernel table without it being complained about. Defaults to\n\"no\".\n\nDestination=\nThe destination prefix of the route. Possibly followed by a slash\nand the prefix length. If omitted, a full-length host route is\nassumed.\n\nSource=\nThe source prefix of the route. Possibly followed by a slash and\nthe prefix length. If omitted, a full-length host route is assumed.\n\nMetric=\nThe metric of the route. Takes an unsigned integer in the range\n0...4294967295. Defaults to unset, and the kernel's default will be\nused.\n\nIPv6Preference=\nSpecifies the route preference as defined in RFC 4191[15] for\nRouter Discovery messages. Which can be one of \"low\" the route has\na lowest priority, \"medium\" the route has a default priority or\n\"high\" the route has a highest priority.\n\nScope=\nThe scope of the IPv4 route, which can be \"global\", \"site\", \"link\",\n\"host\", or \"nowhere\":\n\no \"global\" means the route can reach hosts more than one hop\naway.\n\no \"site\" means an interior route in the local autonomous system.\n\no \"link\" means the route can only reach hosts on the local\nnetwork (one hop away).\n\no \"host\" means the route will not leave the local machine (used\nfor internal addresses like 127.0.0.1).\n\no \"nowhere\" means the destination doesn't exist.\n\nFor IPv4 route, defaults to \"host\" if Type= is \"local\" or \"nat\",\nand \"link\" if Type= is \"broadcast\", \"multicast\", or \"anycast\". In\nother cases, defaults to \"global\". The value is not used for IPv6.\n\nPreferredSource=\nThe preferred source address of the route. The address must be in\nthe format described in inetpton(3).\n\nTable=\nThe table identifier for the route. Takes one of predefined names\n\"default\", \"main\", and \"local\", and names defined in RouteTable= in\nnetworkd.conf(5), or a number between 1 and 4294967295. The table\ncan be retrieved using ip route show table num. If unset and Type=\nis \"local\", \"broadcast\", \"anycast\", or \"nat\", then \"local\" is used.\nIn other cases, defaults to \"main\".\n\nProtocol=\nThe protocol identifier for the route. Takes a number between 0 and\n255 or the special values \"kernel\", \"boot\", \"static\", \"ra\" and\n\"dhcp\". Defaults to \"static\".\n\nType=\nSpecifies the type for the route. Takes one of \"unicast\", \"local\",\n\"broadcast\", \"anycast\", \"multicast\", \"blackhole\", \"unreachable\",\n\"prohibit\", \"throw\", \"nat\", and \"xresolve\". If \"unicast\", a regular\nroute is defined, i.e. a route indicating the path to take to a\ndestination network address. If \"blackhole\", packets to the defined\nroute are discarded silently. If \"unreachable\", packets to the\ndefined route are discarded and the ICMP message \"Host Unreachable\"\nis generated. If \"prohibit\", packets to the defined route are\ndiscarded and the ICMP message \"Communication Administratively\nProhibited\" is generated. If \"throw\", route lookup in the current\nrouting table will fail and the route selection process will return\nto Routing Policy Database (RPDB). Defaults to \"unicast\".\n\nInitialCongestionWindow=\nThe TCP initial congestion window is used during the start of a TCP\nconnection. During the start of a TCP session, when a client\nrequests a resource, the server's initial congestion window\ndetermines how many packets will be sent during the initial burst\nof data without waiting for acknowledgement. Takes a number between\n1 and 1023. Note that 100 is considered an extremely large value\nfor this option. When unset, the kernel's default (typically 10)\nwill be used.\n\nInitialAdvertisedReceiveWindow=\nThe TCP initial advertised receive window is the amount of receive\ndata (in bytes) that can initially be buffered at one time on a\nconnection. The sending host can send only that amount of data\nbefore waiting for an acknowledgment and window update from the\nreceiving host. Takes a number between 1 and 1023. Note that 100 is\nconsidered an extremely large value for this option. When unset,\nthe kernel's default will be used.\n\nQuickAck=\nTakes a boolean. When true enables TCP quick ack mode for the\nroute. When unset, the kernel's default will be used.\n\nFastOpenNoCookie=\nTakes a boolean. When true enables TCP fastopen without a cookie on\na per-route basis. When unset, the kernel's default will be used.\n\nTTLPropagate=\nTakes a boolean. When true enables TTL propagation at Label\nSwitched Path (LSP) egress. When unset, the kernel's default will\nbe used.\n\nMTUBytes=\nThe maximum transmission unit in bytes to set for the route. The\nusual suffixes K, M, G, are supported and are understood to the\nbase of 1024.\n\nNote that if IPv6 is enabled on the interface, and the MTU is\nchosen below 1280 (the minimum MTU for IPv6) it will automatically\nbe increased to this value.\n\nIPServiceType=\nTakes string; \"CS6\" or \"CS4\". Used to set IP service type to CS6\n(network control) or CS4 (Realtime). Defaults to CS6.\n\nTCPAdvertisedMaximumSegmentSize=\nSpecifies the Path MSS (in bytes) hints given on TCP layer. The\nusual suffixes K, M, G, are supported and are understood to the\nbase of 1024. An unsigned integer in the range 1-4294967294. When\nunset, the kernel's default will be used.\n\nMultiPathRoute=address[@name] [weight]\nConfigures multipath route. Multipath routing is the technique of\nusing multiple alternative paths through a network. Takes gateway\naddress. Optionally, takes a network interface name or index\nseparated with \"@\", and a weight in 1..256 for this multipath route\nseparated with whitespace. This setting can be specified multiple\ntimes. If an empty string is assigned, then the all previous\nassignments are cleared.\n\nNextHop=\nSpecifies the nexthop id. Takes an unsigned integer in the range\n1...4294967295. If set, the corresponding [NextHop] section must be\nconfigured. Defaults to unset.\n\n[DHCPV4] SECTION OPTIONS\nThe [DHCPv4] section configures the DHCPv4 client, if it is enabled\nwith the DHCP= setting described above:\n\nSendHostname=\nWhen true (the default), the machine's hostname (or the value\nspecified with Hostname=, described below) will be sent to the DHCP\nserver. Note that the hostname must consist only of 7-bit ASCII\nlower-case characters and no spaces or dots, and be formatted as a\nvalid DNS domain name. Otherwise, the hostname is not sent even if\nthis option is true.\n\nHostname=\nUse this value for the hostname which is sent to the DHCP server,\ninstead of machine's hostname. Note that the specified hostname\nmust consist only of 7-bit ASCII lower-case characters and no\nspaces or dots, and be formatted as a valid DNS domain name.\n\nMUDURL=\nWhen configured, the specified Manufacturer Usage Description (MUD)\nURL will be sent to the DHCPv4 server. Takes a URL of length up to\n255 characters. A superficial verification that the string is a\nvalid URL will be performed. DHCPv4 clients are intended to have at\nmost one MUD URL associated with them. See RFC 8520[16].\n\nMUD is an embedded software standard defined by the IETF that\nallows IoT device makers to advertise device specifications,\nincluding the intended communication patterns for their device when\nit connects to the network. The network can then use this to author\na context-specific access policy, so the device functions only\nwithin those parameters.\n\nClientIdentifier=\nThe DHCPv4 client identifier to use. Takes one of mac, duid or\nduid-only. If set to mac, the MAC address of the link is used. If\nset to duid, an RFC4361-compliant Client ID, which is the\ncombination of IAID and DUID (see below), is used. If set to\nduid-only, only DUID is used, this may not be RFC compliant, but\nsome setups may require to use this. Defaults to duid.\n\nVendorClassIdentifier=\nThe vendor class identifier used to identify vendor type and\nconfiguration.\n\nUserClass=\nA DHCPv4 client can use UserClass option to identify the type or\ncategory of user or applications it represents. The information\ncontained in this option is a string that represents the user class\nof which the client is a member. Each class sets an identifying\nstring of information to be used by the DHCP service to classify\nclients. Takes a whitespace-separated list of strings.\n\nDUIDType=\nOverride the global DUIDType= setting for this network. See\nnetworkd.conf(5) for a description of possible values.\n\nDUIDRawData=\nOverride the global DUIDRawData= setting for this network. See\nnetworkd.conf(5) for a description of possible values.\n\nIAID=\nThe DHCP Identity Association Identifier (IAID) for the interface,\na 32-bit unsigned integer.\n\nAnonymize=\nTakes a boolean. When true, the options sent to the DHCP server\nwill follow the RFC 7844[17] (Anonymity Profiles for DHCP Clients)\nto minimize disclosure of identifying information. Defaults to\nfalse.\n\nThis option should only be set to true when MACAddressPolicy= is\nset to random (see systemd.link(5)).\n\nWhen true, SendHostname=, ClientIdentifier=,\nVendorClassIdentifier=, UserClass=, RequestOptions=, SendOption=,\nSendVendorOption=, and MUDURL= are ignored.\n\nWith this option enabled DHCP requests will mimic those generated\nby Microsoft Windows, in order to reduce the ability to fingerprint\nand recognize installations. This means DHCP request sizes will\ngrow and lease data will be more comprehensive than normally,\nthough most of the requested data is not actually used.\n\nRequestOptions=\nSets request options to be sent to the server in the DHCPv4 request\noptions list. A whitespace-separated list of integers in the range\n1...254. Defaults to unset.\n\nSendOption=\nSend an arbitrary raw option in the DHCPv4 request. Takes a DHCP\noption number, data type and data separated with a colon\n(\"option:type:value\"). The option number must be an integer in the\nrange 1...254. The type takes one of \"uint8\", \"uint16\", \"uint32\",\n\"ipv4address\", or \"string\". Special characters in the data string\nmay be escaped using C-style escapes[18]. This setting can be\nspecified multiple times. If an empty string is specified, then all\noptions specified earlier are cleared. Defaults to unset.\n\nSendVendorOption=\nSend an arbitrary vendor option in the DHCPv4 request. Takes a DHCP\noption number, data type and data separated with a colon\n(\"option:type:value\"). The option number must be an integer in the\nrange 1...254. The type takes one of \"uint8\", \"uint16\", \"uint32\",\n\"ipv4address\", or \"string\". Special characters in the data string\nmay be escaped using C-style escapes[18]. This setting can be\nspecified multiple times. If an empty string is specified, then all\noptions specified earlier are cleared. Defaults to unset.\n\nUseDNS=\nWhen true (the default), the DNS servers received from the DHCP\nserver will be used.\n\nThis corresponds to the nameserver option in resolv.conf(5).\n\nRoutesToDNS=\nWhen true, the routes to the DNS servers received from the DHCP\nserver will be configured. When UseDNS= is disabled, this setting\nis ignored. Defaults to true.\n\nUseNTP=\nWhen true (the default), the NTP servers received from the DHCP\nserver will be used by systemd-timesyncd.service.\n\nRoutesToNTP=\nWhen true, the routes to the NTP servers received from the DHCP\nserver will be configured. When UseNTP= is disabled, this setting\nis ignored. Defaults to true.\n\nUseSIP=\nWhen true (the default), the SIP servers received from the DHCP\nserver will be collected and made available to client programs.\n\nUseMTU=\nWhen true, the interface maximum transmission unit from the DHCP\nserver will be used on the current link. If MTUBytes= is set, then\nthis setting is ignored. Defaults to false.\n\nUseHostname=\nWhen true (the default), the hostname received from the DHCP server\nwill be set as the transient hostname of the system.\n\nUseDomains=\nTakes a boolean, or the special value route. When true, the domain\nname received from the DHCP server will be used as DNS search\ndomain over this link, similar to the effect of the Domains=\nsetting. If set to route, the domain name received from the DHCP\nserver will be used for routing DNS queries only, but not for\nsearching, similar to the effect of the Domains= setting when the\nargument is prefixed with \"~\". Defaults to true on Ubuntu.\n\nIt is recommended to enable this option only on trusted networks,\nas setting this affects resolution of all hostnames, in particular\nof single-label names. It is generally safer to use the supplied\ndomain only as routing domain, rather than as search domain, in\norder to not have it affect local resolution of single-label names.\n\nWhen set to true, this setting corresponds to the domain option in\nresolv.conf(5).\n\nUseRoutes=\nWhen true (the default), the static routes will be requested from\nthe DHCP server and added to the routing table with a metric of\n1024, and a scope of global, link or host, depending on the route's\ndestination and gateway. If the destination is on the local host,\ne.g., 127.x.x.x, or the same as the link's own address, the scope\nwill be set to host. Otherwise if the gateway is null (a direct\nroute), a link scope will be used. For anything else, scope\ndefaults to global.\n\nRouteMetric=\nSet the routing metric for routes specified by the DHCP server.\nTakes an unsigned integer in the range 0...4294967295. Defaults to\n1024.\n\nRouteTable=num\nThe table identifier for DHCP routes (a number between 1 and\n4294967295, or 0 to unset). The table can be retrieved using ip\nroute show table num.\n\nWhen used in combination with VRF=, the VRF's routing table is used\nwhen this parameter is not specified.\n\nRouteMTUBytes=\nSpecifies the MTU for the DHCP routes. Please see the [Route]\nsection for further details.\n\nUseGateway=\nWhen true, the gateway will be requested from the DHCP server and\nadded to the routing table with a metric of 1024, and a scope of\nlink. When unset, the value specified with UseRoutes= is used.\n\nUseTimezone=\nWhen true, the timezone received from the DHCP server will be set\nas timezone of the local system. Defaults to false.\n\nFallbackLeaseLifetimeSec=\nAllows to set DHCPv4 lease lifetime when DHCPv4 server does not\nsend the lease lifetime. Takes one of \"forever\" or \"infinity\". The\nlatter means that the address never expires. Defaults to unset.\n\nRequestBroadcast=\nRequest the server to use broadcast messages before the IP address\nhas been configured. This is necessary for devices that cannot\nreceive RAW packets, or that cannot receive packets at all before\nan IP address has been configured. On the other hand, this must not\nbe enabled on networks where broadcasts are filtered out.\n\nMaxAttempts=\nSpecifies how many times the DHCPv4 client configuration should be\nattempted. Takes a number or \"infinity\". Defaults to \"infinity\".\nNote that the time between retries is increased exponentially, up\nto approximately one per minute, so the network will not be\noverloaded even if this number is high. The default is suitable in\nmost circumstances.\n\nListenPort=\nSet the port from which the DHCP client packets originate.\n\nDenyList=\nA whitespace-separated list of IPv4 addresses. DHCP offers from\nservers in the list are rejected. Note that if AllowList= is\nconfigured then DenyList= is ignored.\n\nAllowList=\nA whitespace-separated list of IPv4 addresses. DHCP offers from\nservers in the list are accepted.\n\nSendRelease=\nWhen true, the DHCPv4 client sends a DHCP release packet when it\nstops. Defaults to true.\n\nSendDecline=\nA boolean. When \"true\", the DHCPv4 client receives the IP address\nfrom the DHCP server. After a new IP is received, the DHCPv4 client\nperforms IPv4 Duplicate Address Detection. If duplicate use is\ndetected, the DHCPv4 client rejects the IP by sending a DHCPDECLINE\npacket and tries to obtain an IP address again. See RFC 5224[11].\nDefaults to \"unset\".\n\n[DHCPV6] SECTION OPTIONS\nThe [DHCPv6] section configures the DHCPv6 client, if it is enabled\nwith the DHCP= setting described above, or invoked by the IPv6 Router\nAdvertisement:\n\nMUDURL=, IAID=, DUIDType=, DUIDRawData=, RequestOptions=\nAs in the [DHCPv4] section.\n\nSendOption=\nAs in the [DHCPv4] section, however because DHCPv6 uses 16-bit\nfields to store option numbers, the option number is an integer in\nthe range 1...65536.\n\nSendVendorOption=\nSend an arbitrary vendor option in the DHCPv6 request. Takes an\nenterprise identifier, DHCP option number, data type, and data\nseparated with a colon (\"enterprise identifier:option:type:value\").\nEnterprise identifier is an unsigned integer in the range\n1...4294967294. The option number must be an integer in the range\n1...254. Data type takes one of \"uint8\", \"uint16\", \"uint32\",\n\"ipv4address\", \"ipv6address\", or \"string\". Special characters in\nthe data string may be escaped using C-style escapes[18]. This\nsetting can be specified multiple times. If an empty string is\nspecified, then all options specified earlier are cleared. Defaults\nto unset.\n\nUserClass=\nA DHCPv6 client can use User Class option to identify the type or\ncategory of user or applications it represents. The information\ncontained in this option is a string that represents the user class\nof which the client is a member. Each class sets an identifying\nstring of information to be used by the DHCP service to classify\nclients. Special characters in the data string may be escaped using\nC-style escapes[18]. This setting can be specified multiple times.\nIf an empty string is specified, then all options specified earlier\nare cleared. Takes a whitespace-separated list of strings. Note\nthat currently NUL bytes are not allowed.\n\nVendorClass=\nA DHCPv6 client can use VendorClass option to identify the vendor\nthat manufactured the hardware on which the client is running. The\ninformation contained in the data area of this option is contained\nin one or more opaque fields that identify details of the hardware\nconfiguration. Takes a whitespace-separated list of strings.\n\nPrefixDelegationHint=\nTakes an IPv6 address with prefix length in the same format as the\nAddress= in the [Network] section. The DHCPv6 client will include a\nprefix hint in the DHCPv6 solicitation sent to the server. The\nprefix length must be in the range 1-128. Defaults to unset.\n\nUseAddress=\nWhen true (the default), the IP addresses provided by the DHCPv6\nserver will be assigned.\n\nUseDNS=, UseNTP=, UseHostname=, UseDomains=\nAs in the [DHCPv4] section.\n\nForceDHCPv6PDOtherInformation=\nTakes a boolean that enforces DHCPv6 stateful mode when the 'Other\ninformation' bit is set in Router Advertisement messages. By\ndefault setting only the 'O' bit in Router Advertisements makes\nDHCPv6 request network information in a stateless manner using a\ntwo-message Information Request and Information Reply message\nexchange. RFC 7084[19], requirement WPD-4, updates this behavior\nfor a Customer Edge router so that stateful DHCPv6 Prefix\nDelegation is also requested when only the 'O' bit is set in Router\nAdvertisements. This option enables such a CE behavior as it is\nimpossible to automatically distinguish the intention of the 'O'\nbit otherwise. By default this option is set to false, enable it if\nno prefixes are delegated when the device should be acting as a CE\nrouter.\n\nWithoutRA=\nAllows DHCPv6 client to start without router advertisements's\nmanaged or other address configuration flag. Takes one of \"solicit\"\nor \"information-request\". Defaults to unset.\n\nRapidCommit=\nTakes a boolean. The DHCPv6 client can obtain configuration\nparameters from a DHCPv6 server through a rapid two-message\nexchange (solicit and reply). When the rapid commit option is\nenabled by both the DHCPv6 client and the DHCPv6 server, the\ntwo-message exchange is used, rather than the default four-message\nexchange (solicit, advertise, request, and reply). The two-message\nexchange provides faster client configuration and is beneficial in\nenvironments in which networks are under a heavy load. See RFC\n3315[20] for details. Defaults to true.\n\n[DHCPV6PREFIXDELEGATION] SECTION OPTIONS\nThe [DHCPv6PrefixDelegation] section configures delegated prefixes\nassigned by DHCPv6 server. The settings in this section are used only\nwhen DHCPv6PrefixDelegation= setting is enabled.\n\nSubnetId=\nConfigure a specific subnet ID on the interface from a (previously)\nreceived prefix delegation. You can either set \"auto\" (the default)\nor a specific subnet ID (as defined in RFC 4291[21], section\n2.5.4), in which case the allowed value is hexadecimal, from 0 to\n0x7fffffffffffffff inclusive.\n\nAnnounce=\nTakes a boolean. When enabled, and IPv6SendRA= in [Network] section\nis enabled, the delegated prefixes are distributed through the IPv6\nRouter Advertisement. Defaults to yes.\n\nAssign=\nTakes a boolean. Specifies whether to add an address from the\ndelegated prefixes which are received from the WAN interface by the\nDHCPv6 Prefix Delegation. When true (on LAN interfce), the EUI-64\nalgorithm will be used by default to form an interface identifier\nfrom the delegated prefixes. See also Token= setting below.\nDefaults to yes.\n\nToken=\nSpecifies an optional address generation mode for assigning an\naddress in each delegated prefix. Takes an IPv6 address. When set,\nthe lower bits of the supplied address is combined with the upper\nbits of each delegatad prefix received from the WAN interface by\nthe DHCPv6 Prefix Delegation to form a complete address. When\nAssign= is disabled, this setting is ignored. When unset, the\nEUI-64 algorithm will be used to form addresses. Defaults to unset.\n\nManageTemporaryAddress=\nAs in the [Address] section, but defaults to true.\n\nRouteMetric=\nThe metric of the route to the delegated prefix subnet. Takes an\nunsigned integer in the range 0...4294967295. When unset or set to\n0, the kernel's default value is used.\n\n[IPV6ACCEPTRA] SECTION OPTIONS\nThe [IPv6AcceptRA] section configures the IPv6 Router Advertisement\n(RA) client, if it is enabled with the IPv6AcceptRA= setting described\nabove:\n\nUseDNS=\nWhen true (the default), the DNS servers received in the Router\nAdvertisement will be used.\n\nThis corresponds to the nameserver option in resolv.conf(5).\n\nUseDomains=\nTakes a boolean, or the special value \"route\". When true, the\ndomain name received via IPv6 Router Advertisement (RA) will be\nused as DNS search domain over this link, similar to the effect of\nthe Domains= setting. If set to \"route\", the domain name received\nvia IPv6 RA will be used for routing DNS queries only, but not for\nsearching, similar to the effect of the Domains= setting when the\nargument is prefixed with \"~\". Defaults to true on Ubuntu.\n\nIt is recommended to enable this option only on trusted networks,\nas setting this affects resolution of all hostnames, in particular\nof single-label names. It is generally safer to use the supplied\ndomain only as routing domain, rather than as search domain, in\norder to not have it affect local resolution of single-label names.\n\nWhen set to true, this setting corresponds to the domain option in\nresolv.conf(5).\n\nRouteTable=num\nThe table identifier for the routes received in the Router\nAdvertisement (a number between 1 and 4294967295, or 0 to unset).\nThe table can be retrieved using ip route show table num.\n\nRouteMetric=\nSet the routing metric for the routes received in the Router\nAdvertisement. Takes an unsigned integer in the range\n0...4294967295. Defaults to 1024.\n\nUseAutonomousPrefix=\nWhen true (the default), the autonomous prefix received in the\nRouter Advertisement will be used and take precedence over any\nstatically configured ones.\n\nUseOnLinkPrefix=\nWhen true (the default), the onlink prefix received in the Router\nAdvertisement will be used and takes precedence over any statically\nconfigured ones.\n\nRouterDenyList=\nA whitespace-separated list of IPv6 router addresses. Any\ninformation advertised by the listed router is ignored.\n\nRouterAllowList=\nA whitespace-separated list of IPv6 router addresses. Only\ninformation advertised by the listed router is accepted. Note that\nif RouterAllowList= is configured then RouterDenyList= is ignored.\n\nPrefixDenyList=\nA whitespace-separated list of IPv6 prefixes. IPv6 prefixes\nsupplied via router advertisements in the list are ignored.\n\nPrefixAllowList=\nA whitespace-separated list of IPv6 prefixes. IPv6 prefixes\nsupplied via router advertisements in the list are allowed. Note\nthat if PrefixAllowList= is configured then PrefixDenyList= is\nignored.\n\nRouteDenyList=\nA whitespace-separated list of IPv6 route prefixes. IPv6 route\nprefixes supplied via router advertisements in the list are\nignored.\n\nRouteAllowList=\nA whitespace-separated list of IPv6 route prefixes. IPv6 route\nprefixes supplied via router advertisements in the list are\nallowed. Note that if RouteAllowList= is configured then\nRouteDenyList= is ignored.\n\nDHCPv6Client=\nTakes a boolean, or the special value \"always\". When true or\n\"always\", the DHCPv6 client will be started when the RA has the\nmanaged or other information flag. If set to \"always\", the DHCPv6\nclient will also be started in managed mode when neither managed\nnor other information flag is set in the RA. Defaults to true.\n\n[DHCPSERVER] SECTION OPTIONS\nThe [DHCPServer] section contains settings for the DHCP server, if\nenabled via the DHCPServer= option described above:\n\nServerAddress=\nSpecifies server address for the DHCP server. Takes an IPv4 address\nwith prefix length, for example \"192.168.0.1/24\". This setting may\nbe useful when the link on which the DHCP server is running has\nmultiple static addresses. When unset, one of static addresses in\nthe link will be automatically selected. Defaults to unset.\n\nPoolOffset=, PoolSize=\nConfigures the pool of addresses to hand out. The pool is a\ncontiguous sequence of IP addresses in the subnet configured for\nthe server address, which does not include the subnet nor the\nbroadcast address. PoolOffset= takes the offset of the pool from\nthe start of subnet, or zero to use the default value. PoolSize=\ntakes the number of IP addresses in the pool or zero to use the\ndefault value. By default, the pool starts at the first address\nafter the subnet address and takes up the rest of the subnet,\nexcluding the broadcast address. If the pool includes the server\naddress (the default), this is reserved and not handed out to\nclients.\n\nDefaultLeaseTimeSec=, MaxLeaseTimeSec=\nControl the default and maximum DHCP lease time to pass to clients.\nThese settings take time values in seconds or another common time\nunit, depending on the suffix. The default lease time is used for\nclients that did not ask for a specific lease time. If a client\nasks for a lease time longer than the maximum lease time, it is\nautomatically shortened to the specified time. The default lease\ntime defaults to 1h, the maximum lease time to 12h. Shorter lease\ntimes are beneficial if the configuration data in DHCP leases\nchanges frequently and clients shall learn the new settings with\nshorter latencies. Longer lease times reduce the generated DHCP\nnetwork traffic.\n\nUplinkInterface=\nSpecifies name or index of uplink interface, or one of the special\nvalues \":none\" and \":auto\". When emitting DNS, NTP, or SIP servers\nare enabled but no servers are specified, the servers configured in\nthe uplink interface will be emitted. When \":auto\", the link which\nhas default gateway with higher priority will be automatically\nselected. When \":none\", no uplink interface will be selected.\nDefaults to \":auto\".\n\nEmitDNS=, DNS=\nEmitDNS= takes a boolean. Configures whether the DHCP leases handed\nout to clients shall contain DNS server information. Defaults to\n\"yes\". The DNS servers to pass to clients may be configured with\nthe DNS= option, which takes a list of IPv4 addresses. If the\nEmitDNS= option is enabled but no servers configured, the servers\nare automatically propagated from an \"uplink\" interface that has\nappropriate servers set. The \"uplink\" interface is determined by\nthe default route of the system with the highest priority. Note\nthat this information is acquired at the time the lease is handed\nout, and does not take uplink interfaces into account that acquire\nDNS server information at a later point. If no suitable uplink\ninterface is found the DNS server data from /etc/resolv.conf is\nused. Also, note that the leases are not refreshed if the uplink\nnetwork configuration changes. To ensure clients regularly acquire\nthe most current uplink DNS server information, it is thus\nadvisable to shorten the DHCP lease time via MaxLeaseTimeSec=\ndescribed above.\n\nEmitNTP=, NTP=, EmitSIP=, SIP=, EmitPOP3=, POP3=, EmitSMTP=, SMTP=,\nEmitLPR=, LPR=\nSimilar to the EmitDNS= and DNS= settings described above, these\nsettings configure whether and what server information for the\nindicate protocol shall be emitted as part of the DHCP lease. The\nsame syntax, propagation semantics and defaults apply as for\nEmitDNS= and DNS=.\n\nEmitRouter=\nSimilar to the EmitDNS= setting described above, this setting\nconfigures whether the DHCP lease should contain the router option.\nThe same syntax, propagation semantics and defaults apply as for\nEmitDNS=.\n\nEmitTimezone=, Timezone=\nTakes a boolean. Configures whether the DHCP leases handed out to\nclients shall contain timezone information. Defaults to \"yes\". The\nTimezone= setting takes a timezone string (such as \"Europe/Berlin\"\nor \"UTC\") to pass to clients. If no explicit timezone is set, the\nsystem timezone of the local host is propagated, as determined by\nthe /etc/localtime symlink.\n\nSendOption=\nSend a raw option with value via DHCPv4 server. Takes a DHCP option\nnumber, data type and data (\"option:type:value\"). The option number\nis an integer in the range 1...254. The type takes one of \"uint8\",\n\"uint16\", \"uint32\", \"ipv4address\", \"ipv6address\", or \"string\".\nSpecial characters in the data string may be escaped using C-style\nescapes[18]. This setting can be specified multiple times. If an\nempty string is specified, then all options specified earlier are\ncleared. Defaults to unset.\n\nSendVendorOption=\nSend a vendor option with value via DHCPv4 server. Takes a DHCP\noption number, data type and data (\"option:type:value\"). The option\nnumber is an integer in the range 1...254. The type takes one of\n\"uint8\", \"uint16\", \"uint32\", \"ipv4address\", or \"string\". Special\ncharacters in the data string may be escaped using C-style\nescapes[18]. This setting can be specified multiple times. If an\nempty string is specified, then all options specified earlier are\ncleared. Defaults to unset.\n\nBindToInterface=\nTakes a boolean value. When \"yes\", DHCP server socket will be bound\nto its network interface and all socket communication will be\nrestricted to this interface. Defaults to \"yes\", except if\nRelayTarget= is used (see below), in which case it defaults\ndefaults to \"no\".\n\nRelayTarget=\nTakes an IPv4 address, which must be in the format described in\ninetpton(3). Turns this DHCP server into a DHCP relay agent. See\nRFC 1542[22]. The address is the address of DHCP server or another\nrelay agent to forward DHCP messages to and from.\n\nRelayAgentCircuitId=\nSpecifies value for Agent Circuit ID suboption of Relay Agent\nInformation option. Takes a string, which must be in the format\n\"string:value\", where \"value\" should be replaced with the value of\nthe suboption. Defaults to unset (means no Agent Circuit ID\nsuboption is generated). Ignored if RelayTarget= is not specified.\n\nRelayAgentRemoteId=\nSpecifies value for Agent Remote ID suboption of Relay Agent\nInformation option. Takes a string, which must be in the format\n\"string:value\", where \"value\" should be replaced with the value of\nthe suboption. Defaults to unset (means no Agent Remote ID\nsuboption is generated). Ignored if RelayTarget= is not specified.\n\n[DHCPSERVERSTATICLEASE] SECTION OPTIONS\nThe \"[DHCPServerStaticLease]\" section configures a static DHCP lease to\nassign a fixed IPv4 address to a specific device based on its MAC\naddress. This section can be specified multiple times.\n\nMACAddress=\nThe hardware address of a device to match. This key is mandatory.\n\nAddress=\nThe IPv4 address that should be assigned to the device that was\nmatched with MACAddress=. This key is mandatory.\n\n[IPV6SENDRA] SECTION OPTIONS\nThe [IPv6SendRA] section contains settings for sending IPv6 Router\nAdvertisements and whether to act as a router, if enabled via the\nIPv6SendRA= option described above. IPv6 network prefixes or routes are\ndefined with one or more [IPv6Prefix] or [IPv6RoutePrefix] sections.\n\nManaged=, OtherInformation=\nTakes a boolean. Controls whether a DHCPv6 server is used to\nacquire IPv6 addresses on the network link when Managed= is set to\n\"true\" or if only additional network information can be obtained\nvia DHCPv6 for the network link when OtherInformation= is set to\n\"true\". Both settings default to \"false\", which means that a DHCPv6\nserver is not being used.\n\nRouterLifetimeSec=\nTakes a timespan. Configures the IPv6 router lifetime in seconds.\nWhen set to 0, the host is not acting as a router. Defaults to 30\nminutes.\n\nRouterPreference=\nConfigures IPv6 router preference if RouterLifetimeSec= is\nnon-zero. Valid values are \"high\", \"medium\" and \"low\", with\n\"normal\" and \"default\" added as synonyms for \"medium\" just to make\nconfiguration easier. See RFC 4191[15] for details. Defaults to\n\"medium\".\n\nEmitDNS=, DNS=\nDNS= specifies a list of recursive DNS server IPv6 addresses that\nare distributed via Router Advertisement messages when EmitDNS= is\ntrue. DNS= also takes special value \"linklocal\"; in that case\nthe IPv6 link local address is distributed. If DNS= is empty, DNS\nservers are read from the [Network] section. If the [Network]\nsection does not contain any DNS servers either, DNS servers from\nthe uplink with the highest priority default route are used. When\nEmitDNS= is false, no DNS server information is sent in Router\nAdvertisement messages. EmitDNS= defaults to true.\n\nEmitDomains=, Domains=\nA list of DNS search domains distributed via Router Advertisement\nmessages when EmitDomains= is true. If Domains= is empty, DNS\nsearch domains are read from the [Network] section. If the\n[Network] section does not contain any DNS search domains either,\nDNS search domains from the uplink with the highest priority\ndefault route are used. When EmitDomains= is false, no DNS search\ndomain information is sent in Router Advertisement messages.\nEmitDomains= defaults to true.\n\nDNSLifetimeSec=\nLifetime in seconds for the DNS server addresses listed in DNS= and\nsearch domains listed in Domains=.\n\n[IPV6PREFIX] SECTION OPTIONS\nOne or more [IPv6Prefix] sections contain the IPv6 prefixes that are\nannounced via Router Advertisements. See RFC 4861[23] for further\ndetails.\n\nAddressAutoconfiguration=, OnLink=\nTakes a boolean to specify whether IPv6 addresses can be\nautoconfigured with this prefix and whether the prefix can be used\nfor onlink determination. Both settings default to \"true\" in order\nto ease configuration.\n\nPrefix=\nThe IPv6 prefix that is to be distributed to hosts. Similarly to\nconfiguring static IPv6 addresses, the setting is configured as an\nIPv6 prefix and its prefix length, separated by a \"/\" character.\nUse multiple [IPv6Prefix] sections to configure multiple IPv6\nprefixes since prefix lifetimes, address autoconfiguration and\nonlink status may differ from one prefix to another.\n\nPreferredLifetimeSec=, ValidLifetimeSec=\nPreferred and valid lifetimes for the prefix measured in seconds.\nPreferredLifetimeSec= defaults to 604800 seconds (one week) and\nValidLifetimeSec= defaults to 2592000 seconds (30 days).\n\nAssign=\nTakes a boolean. When true, adds an address from the prefix.\nDefault to false.\n\nRouteMetric=\nThe metric of the prefix route. Takes an unsigned integer in the\nrange 0...4294967295. When unset or set to 0, the kernel's default\nvalue is used. This setting is ignored when Assign= is false.\n\n[IPV6ROUTEPREFIX] SECTION OPTIONS\nOne or more [IPv6RoutePrefix] sections contain the IPv6 prefix routes\nthat are announced via Router Advertisements. See RFC 4191[15] for\nfurther details.\n\nRoute=\nThe IPv6 route that is to be distributed to hosts. Similarly to\nconfiguring static IPv6 routes, the setting is configured as an\nIPv6 prefix routes and its prefix route length, separated by a \"/\"\ncharacter. Use multiple [IPv6PrefixRoutes] sections to configure\nmultiple IPv6 prefix routes.\n\nLifetimeSec=\nLifetime for the route prefix measured in seconds. LifetimeSec=\ndefaults to 604800 seconds (one week).\n\n[BRIDGE] SECTION OPTIONS\nThe [Bridge] section accepts the following keys:\n\nUnicastFlood=\nTakes a boolean. Controls whether the bridge should flood traffic\nfor which an FDB entry is missing and the destination is unknown\nthrough this port. When unset, the kernel's default will be used.\n\nMulticastFlood=\nTakes a boolean. Controls whether the bridge should flood traffic\nfor which an MDB entry is missing and the destination is unknown\nthrough this port. When unset, the kernel's default will be used.\n\nMulticastToUnicast=\nTakes a boolean. Multicast to unicast works on top of the multicast\nsnooping feature of the bridge. Which means unicast copies are only\ndelivered to hosts which are interested in it. When unset, the\nkernel's default will be used.\n\nNeighborSuppression=\nTakes a boolean. Configures whether ARP and ND neighbor suppression\nis enabled for this port. When unset, the kernel's default will be\nused.\n\nLearning=\nTakes a boolean. Configures whether MAC address learning is enabled\nfor this port. When unset, the kernel's default will be used.\n\nHairPin=\nTakes a boolean. Configures whether traffic may be sent back out of\nthe port on which it was received. When this flag is false, then\nthe bridge will not forward traffic back out of the receiving port.\nWhen unset, the kernel's default will be used.\n\nUseBPDU=\nTakes a boolean. Configures whether STP Bridge Protocol Data Units\nwill be processed by the bridge port. When unset, the kernel's\ndefault will be used.\n\nFastLeave=\nTakes a boolean. This flag allows the bridge to immediately stop\nmulticast traffic on a port that receives an IGMP Leave message. It\nis only used with IGMP snooping if enabled on the bridge. When\nunset, the kernel's default will be used.\n\nAllowPortToBeRoot=\nTakes a boolean. Configures whether a given port is allowed to\nbecome a root port. Only used when STP is enabled on the bridge.\nWhen unset, the kernel's default will be used.\n\nProxyARP=\nTakes a boolean. Configures whether proxy ARP to be enabled on this\nport. When unset, the kernel's default will be used.\n\nProxyARPWiFi=\nTakes a boolean. Configures whether proxy ARP to be enabled on this\nport which meets extended requirements by IEEE 802.11 and Hotspot\n2.0 specifications. When unset, the kernel's default will be used.\n\nMulticastRouter=\nConfigures this port for having multicast routers attached. A port\nwith a multicast router will receive all multicast traffic. Takes\none of \"no\" to disable multicast routers on this port, \"query\" to\nlet the system detect the presence of routers, \"permanent\" to\npermanently enable multicast traffic forwarding on this port, or\n\"temporary\" to enable multicast routers temporarily on this port,\nnot depending on incoming queries. When unset, the kernel's default\nwill be used.\n\nCost=\nSets the \"cost\" of sending packets of this interface. Each port in\na bridge may have a different speed and the cost is used to decide\nwhich link to use. Faster interfaces should have lower costs. It is\nan integer value between 1 and 65535.\n\nPriority=\nSets the \"priority\" of sending packets on this interface. Each port\nin a bridge may have a different priority which is used to decide\nwhich link to use. Lower value means higher priority. It is an\ninteger value between 0 to 63. Networkd does not set any default,\nmeaning the kernel default value of 32 is used.\n\n[BRIDGEFDB] SECTION OPTIONS\nThe [BridgeFDB] section manages the forwarding database table of a port\nand accepts the following keys. Specify several [BridgeFDB] sections to\nconfigure several static MAC table entries.\n\nMACAddress=\nAs in the [Network] section. This key is mandatory.\n\nDestination=\nTakes an IP address of the destination VXLAN tunnel endpoint.\n\nVLANId=\nThe VLAN ID for the new static MAC table entry. If omitted, no VLAN\nID information is appended to the new static MAC table entry.\n\nVNI=\nThe VXLAN Network Identifier (or VXLAN Segment ID) to use to\nconnect to the remote VXLAN tunnel endpoint. Takes a number in the\nrange 1...16777215. Defaults to unset.\n\nAssociatedWith=\nSpecifies where the address is associated with. Takes one of \"use\",\n\"self\", \"master\" or \"router\". \"use\" means the address is in use.\nUser space can use this option to indicate to the kernel that the\nfdb entry is in use. \"self\" means the address is associated with\nthe port drivers fdb. Usually hardware. \"master\" means the address\nis associated with master devices fdb. \"router\" means the\ndestination address is associated with a router. Note that it's\nvalid if the referenced device is a VXLAN type device and has route\nshortcircuit enabled. Defaults to \"self\".\n\nOutgoingInterface=\nSpecifies the name or index of the outgoing interface for the VXLAN\ndevice driver to reach the remote VXLAN tunnel endpoint. Defaults\nto unset.\n\n[BRIDGEMDB] SECTION OPTIONS\nThe [BridgeMDB] section manages the multicast membership entries\nforwarding database table of a port and accepts the following keys.\nSpecify several [BridgeMDB] sections to configure several permanent\nmulticast membership entries.\n\nMulticastGroupAddress=\nSpecifies the IPv4 or IPv6 multicast group address to add. This\nsetting is mandatory.\n\nVLANId=\nThe VLAN ID for the new entry. Valid ranges are 0 (no VLAN) to\n4094. Optional, defaults to 0.\n\n[LLDP] SECTION OPTIONS\nThe [LLDP] section manages the Link Layer Discovery Protocol (LLDP) and\naccepts the following keys:\n\nMUDURL=\nWhen configured, the specified Manufacturer Usage Descriptions\n(MUD) URL will be sent in LLDP packets. The syntax and semantics\nare the same as for MUDURL= in the [DHCPv4] section described\nabove.\n\nThe MUD URLs received via LLDP packets are saved and can be read\nusing the sdlldpneighborgetmudurl() function.\n\n[CAN] SECTION OPTIONS\nThe [CAN] section manages the Controller Area Network (CAN bus) and\naccepts the following keys:\n\nBitRate=\nThe bitrate of CAN device in bits per second. The usual SI prefixes\n(K, M) with the base of 1000 can be used here. Takes a number in\nthe range 1...4294967295.\n\nSamplePoint=\nOptional sample point in percent with one decimal (e.g. \"75%\",\n\"87.5%\") or permille (e.g. \"875\").\n\nDataBitRate=, DataSamplePoint=\nThe bitrate and sample point for the data phase, if CAN-FD is used.\nThese settings are analogous to the BitRate= and SamplePoint= keys.\n\nFDMode=\nTakes a boolean. When \"yes\", CAN-FD mode is enabled for the\ninterface. Note, that a bitrate and optional sample point should\nalso be set for the CAN-FD data phase using the DataBitRate= and\nDataSamplePoint= keys.\n\nFDNonISO=\nTakes a boolean. When \"yes\", non-ISO CAN-FD mode is enabled for the\ninterface. When unset, the kernel's default will be used.\n\nRestartSec=\nAutomatic restart delay time. If set to a non-zero value, a restart\nof the CAN controller will be triggered automatically in case of a\nbus-off condition after the specified delay time. Subsecond delays\ncan be specified using decimals (e.g. \"0.1s\") or a \"ms\" or \"us\"\npostfix. Using \"infinity\" or \"0\" will turn the automatic restart\noff. By default automatic restart is disabled.\n\nTermination=\nTakes a boolean. When \"yes\", the termination resistor will be\nselected for the bias network. When unset, the kernel's default\nwill be used.\n\nTripleSampling=\nTakes a boolean. When \"yes\", three samples (instead of one) are\nused to determine the value of a received bit by majority rule.\nWhen unset, the kernel's default will be used.\n\nBusErrorReporting=\nTakes a boolean. When \"yes\", reporting of CAN bus errors is\nactivated (those include single bit, frame format, and bit stuffing\nerrors, unable to send dominant bit, unable to send recessive bit,\nbus overload, active error announcement, error occurred on\ntransmission). When unset, the kernel's default will be used. Note:\nin case of a CAN bus with a single CAN device, sending a CAN frame\nmay result in a huge number of CAN bus errors.\n\nListenOnly=\nTakes a boolean. When \"yes\", listen-only mode is enabled. When the\ninterface is in listen-only mode, the interface neither transmit\nCAN frames nor send ACK bit. Listen-only mode is important to debug\nCAN networks without interfering with the communication or\nacknowledge the CAN frame. When unset, the kernel's default will be\nused.\n\n[QDISC] SECTION OPTIONS\nThe [QDisc] section manages the traffic control queueing discipline\n(qdisc).\n\nParent=\nSpecifies the parent Queueing Discipline (qdisc). Takes one of\n\"clsact\" or \"ingress\". This is mandatory.\n\nHandle=\nConfigures the major number of unique identifier of the qdisc,\nknown as the handle. Takes a hexadecimal number in the range\n0x1-0xffff. Defaults to unset.\n\n[NETWORKEMULATOR] SECTION OPTIONS\nThe [NetworkEmulator] section manages the queueing discipline (qdisc)\nof the network emulator. It can be used to configure the kernel packet\nscheduler and simulate packet delay and loss for UDP or TCP\napplications, or limit the bandwidth usage of a particular service to\nsimulate internet connections.\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", \"clsact\", \"ingress\" or a class identifier. The class\nidentifier is specified as the major and minor numbers in\nhexadecimal in the range 0x1-Oxffff separated with a colon\n(\"major:minor\"). Defaults to \"root\".\n\nHandle=\nConfigures the major number of unique identifier of the qdisc,\nknown as the handle. Takes a hexadecimal number in the range\n0x1-0xffff. Defaults to unset.\n\nDelaySec=\nSpecifies the fixed amount of delay to be added to all packets\ngoing out of the interface. Defaults to unset.\n\nDelayJitterSec=\nSpecifies the chosen delay to be added to the packets outgoing to\nthe network interface. Defaults to unset.\n\nPacketLimit=\nSpecifies the maximum number of packets the qdisc may hold queued\nat a time. An unsigned integer in the range 0-4294967294. Defaults\nto 1000.\n\nLossRate=\nSpecifies an independent loss probability to be added to the\npackets outgoing from the network interface. Takes a percentage\nvalue, suffixed with \"%\". Defaults to unset.\n\nDuplicateRate=\nSpecifies that the chosen percent of packets is duplicated before\nqueuing them. Takes a percentage value, suffixed with \"%\". Defaults\nto unset.\n\n[TOKENBUCKETFILTER] SECTION OPTIONS\nThe [TokenBucketFilter] section manages the queueing discipline (qdisc)\nof token bucket filter (tbf).\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", \"clsact\", \"ingress\" or a class identifier. The class\nidentifier is specified as the major and minor numbers in\nhexadecimal in the range 0x1-Oxffff separated with a colon\n(\"major:minor\"). Defaults to \"root\".\n\nHandle=\nConfigures the major number of unique identifier of the qdisc,\nknown as the handle. Takes a hexadecimal number in the range\n0x1-0xffff. Defaults to unset.\n\nLatencySec=\nSpecifies the latency parameter, which specifies the maximum amount\nof time a packet can sit in the Token Bucket Filter (TBF). Defaults\nto unset.\n\nLimitBytes=\nTakes the number of bytes that can be queued waiting for tokens to\nbecome available. When the size is suffixed with K, M, or G, it is\nparsed as Kilobytes, Megabytes, or Gigabytes, respectively, to the\nbase of 1024. Defaults to unset.\n\nBurstBytes=\nSpecifies the size of the bucket. This is the maximum amount of\nbytes that tokens can be available for instantaneous transfer. When\nthe size is suffixed with K, M, or G, it is parsed as Kilobytes,\nMegabytes, or Gigabytes, respectively, to the base of 1024.\nDefaults to unset.\n\nRate=\nSpecifies the device specific bandwidth. When suffixed with K, M,\nor G, the specified bandwidth is parsed as Kilobits, Megabits, or\nGigabits, respectively, to the base of 1000. Defaults to unset.\n\nMPUBytes=\nThe Minimum Packet Unit (MPU) determines the minimal token usage\n(specified in bytes) for a packet. When suffixed with K, M, or G,\nthe specified size is parsed as Kilobytes, Megabytes, or Gigabytes,\nrespectively, to the base of 1024. Defaults to zero.\n\nPeakRate=\nTakes the maximum depletion rate of the bucket. When suffixed with\nK, M, or G, the specified size is parsed as Kilobits, Megabits, or\nGigabits, respectively, to the base of 1000. Defaults to unset.\n\nMTUBytes=\nSpecifies the size of the peakrate bucket. When suffixed with K, M,\nor G, the specified size is parsed as Kilobytes, Megabytes, or\nGigabytes, respectively, to the base of 1024. Defaults to unset.\n\n[PIE] SECTION OPTIONS\nThe [PIE] section manages the queueing discipline (qdisc) of\nProportional Integral controller-Enhanced (PIE).\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", \"clsact\", \"ingress\" or a class identifier. The class\nidentifier is specified as the major and minor numbers in\nhexadecimal in the range 0x1-Oxffff separated with a colon\n(\"major:minor\"). Defaults to \"root\".\n\nHandle=\nConfigures the major number of unique identifier of the qdisc,\nknown as the handle. Takes a hexadecimal number in the range\n0x1-0xffff. Defaults to unset.\n\nPacketLimit=\nSpecifies the hard limit on the queue size in number of packets.\nWhen this limit is reached, incoming packets are dropped. An\nunsigned integer in the range 1...4294967294. Defaults to unset and\nkernel's default is used.\n\n[FLOWQUEUEPIE] SECTION OPTIONS\nThe \"[FlowQueuePIE]\" section manages the queueing discipline (qdisc) of\nFlow Queue Proportional Integral controller-Enhanced (fqpie).\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", \"clsact\", \"ingress\" or a class identifier. The class\nidentifier is specified as the major and minor numbers in\nhexadecimal in the range 0x1-Oxffff separated with a colon\n(\"major:minor\"). Defaults to \"root\".\n\nHandle=\nConfigures the major number of unique identifier of the qdisc,\nknown as the handle. Takes a hexadecimal number in the range\n0x1-0xffff. Defaults to unset.\n\nPacketLimit=\nSpecifies the hard limit on the queue size in number of packets.\nWhen this limit is reached, incoming packets are dropped. An\nunsigned integer ranges 1 to 4294967294. Defaults to unset and\nkernel's default is used.\n\n[STOCHASTICFAIRBLUE] SECTION OPTIONS\nThe [StochasticFairBlue] section manages the queueing discipline\n(qdisc) of stochastic fair blue (sfb).\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", \"clsact\", \"ingress\" or a class identifier. The class\nidentifier is specified as the major and minor numbers in\nhexadecimal in the range 0x1-Oxffff separated with a colon\n(\"major:minor\"). Defaults to \"root\".\n\nHandle=\nConfigures the major number of unique identifier of the qdisc,\nknown as the handle. Takes a hexadecimal number in the range\n0x1-0xffff. Defaults to unset.\n\nPacketLimit=\nSpecifies the hard limit on the queue size in number of packets.\nWhen this limit is reached, incoming packets are dropped. An\nunsigned integer in the range 0-4294967294. Defaults to unset and\nkernel's default is used.\n\n[STOCHASTICFAIRNESSQUEUEING] SECTION OPTIONS\nThe [StochasticFairnessQueueing] section manages the queueing\ndiscipline (qdisc) of stochastic fairness queueing (sfq).\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", \"clsact\", \"ingress\" or a class identifier. The class\nidentifier is specified as the major and minor numbers in\nhexadecimal in the range 0x1-Oxffff separated with a colon\n(\"major:minor\"). Defaults to \"root\".\n\nHandle=\nConfigures the major number of unique identifier of the qdisc,\nknown as the handle. Takes a hexadecimal number in the range\n0x1-0xffff. Defaults to unset.\n\nPerturbPeriodSec=\nSpecifies the interval in seconds for queue algorithm perturbation.\nDefaults to unset.\n\n[BFIFO] SECTION OPTIONS\nThe [BFIFO] section manages the queueing discipline (qdisc) of Byte\nlimited Packet First In First Out (bfifo).\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", \"clsact\", \"ingress\" or a class identifier. The class\nidentifier is specified as the major and minor numbers in\nhexadecimal in the range 0x1-Oxffff separated with a colon\n(\"major:minor\"). Defaults to \"root\".\n\nHandle=\nConfigures the major number of unique identifier of the qdisc,\nknown as the handle. Takes a hexadecimal number in the range\n0x1-0xffff. Defaults to unset.\n\nLimitBytes=\nSpecifies the hard limit in bytes on the FIFO buffer size. The size\nlimit prevents overflow in case the kernel is unable to dequeue\npackets as quickly as it receives them. When this limit is reached,\nincoming packets are dropped. When suffixed with K, M, or G, the\nspecified size is parsed as Kilobytes, Megabytes, or Gigabytes,\nrespectively, to the base of 1024. Defaults to unset and kernel\ndefault is used.\n\n[PFIFO] SECTION OPTIONS\nThe [PFIFO] section manages the queueing discipline (qdisc) of Packet\nFirst In First Out (pfifo).\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", \"clsact\", \"ingress\" or a class identifier. The class\nidentifier is specified as the major and minor numbers in\nhexadecimal in the range 0x1-Oxffff separated with a colon\n(\"major:minor\"). Defaults to \"root\".\n\nHandle=\nConfigures the major number of unique identifier of the qdisc,\nknown as the handle. Takes a hexadecimal number in the range\n0x1-0xffff. Defaults to unset.\n\nPacketLimit=\nSpecifies the hard limit on the number of packets in the FIFO\nqueue. The size limit prevents overflow in case the kernel is\nunable to dequeue packets as quickly as it receives them. When this\nlimit is reached, incoming packets are dropped. An unsigned integer\nin the range 0-4294967294. Defaults to unset and kernel's default\nis used.\n\n[PFIFOHEADDROP] SECTION OPTIONS\nThe [PFIFOHeadDrop] section manages the queueing discipline (qdisc) of\nPacket First In First Out Head Drop (pfifoheaddrop).\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", \"clsact\", \"ingress\" or a class identifier. The class\nidentifier is specified as the major and minor numbers in\nhexadecimal in the range 0x1-Oxffff separated with a colon\n(\"major:minor\"). Defaults to \"root\".\n\nHandle=\nConfigures the major number of unique identifier of the qdisc,\nknown as the handle. Takes a hexadecimal number in the range\n0x1-0xffff. Defaults to unset.\n\nPacketLimit=\nAs in [PFIFO] section.\n\n[PFIFOFAST] SECTION OPTIONS\nThe [PFIFOFast] section manages the queueing discipline (qdisc) of\nPacket First In First Out Fast (pfifofast).\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", \"clsact\", \"ingress\" or a class identifier. The class\nidentifier is specified as the major and minor numbers in\nhexadecimal in the range 0x1-Oxffff separated with a colon\n(\"major:minor\"). Defaults to \"root\".\n\nHandle=\nConfigures the major number of unique identifier of the qdisc,\nknown as the handle. Takes a hexadecimal number in the range\n0x1-0xffff. Defaults to unset.\n\n[CAKE] SECTION OPTIONS\nThe [CAKE] section manages the queueing discipline (qdisc) of Common\nApplications Kept Enhanced (CAKE).\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", \"clsact\", \"ingress\" or a class identifier. The class\nidentifier is specified as the major and minor numbers in\nhexadecimal in the range 0x1-Oxffff separated with a colon\n(\"major:minor\"). Defaults to \"root\".\n\nHandle=\nConfigures the major number of unique identifier of the qdisc,\nknown as the handle. Takes a hexadecimal number in the range\n0x1-0xffff. Defaults to unset.\n\nOverheadBytes=\nSpecifies that bytes to be addeded to the size of each packet.\nBytes may be negative. Takes an integer in the range from -64 to\n256. Defaults to unset and kernel's default is used.\n\nBandwidth=\nSpecifies the shaper bandwidth. When suffixed with K, M, or G, the\nspecified size is parsed as Kilobits, Megabits, or Gigabits,\nrespectively, to the base of 1000. Defaults to unset and kernel's\ndefault is used.\n\n[CONTROLLEDDELAY] SECTION OPTIONS\nThe [ControlledDelay] section manages the queueing discipline (qdisc)\nof controlled delay (CoDel).\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", \"clsact\", \"ingress\" or a class identifier. The class\nidentifier is specified as the major and minor numbers in\nhexadecimal in the range 0x1-Oxffff separated with a colon\n(\"major:minor\"). Defaults to \"root\".\n\nHandle=\nConfigures the major number of unique identifier of the qdisc,\nknown as the handle. Takes a hexadecimal number in the range\n0x1-0xffff. Defaults to unset.\n\nPacketLimit=\nSpecifies the hard limit on the queue size in number of packets.\nWhen this limit is reached, incoming packets are dropped. An\nunsigned integer in the range 0-4294967294. Defaults to unset and\nkernel's default is used.\n\nTargetSec=\nTakes a timespan. Specifies the acceptable minimum\nstanding/persistent queue delay. Defaults to unset and kernel's\ndefault is used.\n\nIntervalSec=\nTakes a timespan. This is used to ensure that the measured minimum\ndelay does not become too stale. Defaults to unset and kernel's\ndefault is used.\n\nECN=\nTakes a boolean. This can be used to mark packets instead of\ndropping them. Defaults to unset and kernel's default is used.\n\nCEThresholdSec=\nTakes a timespan. This sets a threshold above which all packets are\nmarked with ECN Congestion Experienced (CE). Defaults to unset and\nkernel's default is used.\n\n[DEFICITROUNDROBINSCHEDULER] SECTION OPTIONS\nThe [DeficitRoundRobinScheduler] section manages the queueing\ndiscipline (qdisc) of Deficit Round Robin Scheduler (DRR).\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", \"clsact\", \"ingress\" or a class identifier. The class\nidentifier is specified as the major and minor numbers in\nhexadecimal in the range 0x1-Oxffff separated with a colon\n(\"major:minor\"). Defaults to \"root\".\n\nHandle=\nConfigures the major number of unique identifier of the qdisc,\nknown as the handle. Takes a hexadecimal number in the range\n0x1-0xffff. Defaults to unset.\n\n[DEFICITROUNDROBINSCHEDULERCLASS] SECTION OPTIONS\nThe [DeficitRoundRobinSchedulerClass] section manages the traffic\ncontrol class of Deficit Round Robin Scheduler (DRR).\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", or a qdisc identifier. The qdisc identifier is specified as\nthe major and minor numbers in hexadecimal in the range 0x1-Oxffff\nseparated with a colon (\"major:minor\"). Defaults to \"root\".\n\nClassId=\nConfigures the unique identifier of the class. It is specified as\nthe major and minor numbers in hexadecimal in the range 0x1-Oxffff\nseparated with a colon (\"major:minor\"). Defaults to unset.\n\nQuantumBytes=\nSpecifies the amount of bytes a flow is allowed to dequeue before\nthe scheduler moves to the next class. When suffixed with K, M, or\nG, the specified size is parsed as Kilobytes, Megabytes, or\nGigabytes, respectively, to the base of 1024. Defaults to the MTU\nof the interface.\n\n[ENHANCEDTRANSMISSIONSELECTION] SECTION OPTIONS\nThe [EnhancedTransmissionSelection] section manages the queueing\ndiscipline (qdisc) of Enhanced Transmission Selection (ETS).\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", \"clsact\", \"ingress\" or a class identifier. The class\nidentifier is specified as the major and minor numbers in\nhexadecimal in the range 0x1-Oxffff separated with a colon\n(\"major:minor\"). Defaults to \"root\".\n\nHandle=\nConfigures the major number of unique identifier of the qdisc,\nknown as the handle. Takes a hexadecimal number in the range\n0x1-0xffff. Defaults to unset.\n\nBands=\nSpecifies the number of bands. An unsigned integer in the range\n1-16. This value has to be at least large enough to cover the\nstrict bands specified through the StrictBands= and\nbandwidth-sharing bands specified in QuantumBytes=.\n\nStrictBands=\nSpecifies the number of bands that should be created in strict\nmode. An unsigned integer in the range 1-16.\n\nQuantumBytes=\nSpecifies the white-space separated list of quantum used in\nband-sharing bands. When suffixed with K, M, or G, the specified\nsize is parsed as Kilobytes, Megabytes, or Gigabytes, respectively,\nto the base of 1024. This setting can be specified multiple times.\nIf an empty string is assigned, then the all previous assignments\nare cleared.\n\nPriorityMap=\nThe priority map maps the priority of a packet to a band. The\nargument is a whitespace separated list of numbers. The first\nnumber indicates which band the packets with priority 0 should be\nput to, the second is for priority 1, and so on. There can be up to\n16 numbers in the list. If there are fewer, the default band that\ntraffic with one of the unmentioned priorities goes to is the last\none. Each band number must be in the range 0...255. This setting\ncan be specified multiple times. If an empty string is assigned,\nthen the all previous assignments are cleared.\n\n[GENERICRANDOMEARLYDETECTION] SECTION OPTIONS\nThe [GenericRandomEarlyDetection] section manages the queueing\ndiscipline (qdisc) of Generic Random Early Detection (GRED).\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", \"clsact\", \"ingress\" or a class identifier. The class\nidentifier is specified as the major and minor numbers in\nhexadecimal in the range 0x1-Oxffff separated with a colon\n(\"major:minor\"). Defaults to \"root\".\n\nHandle=\nConfigures the major number of unique identifier of the qdisc,\nknown as the handle. Takes a hexadecimal number in the range\n0x1-0xffff. Defaults to unset.\n\nVirtualQueues=\nSpecifies the number of virtual queues. Takes an integer in the\nrange 1...16. Defaults to unset and kernel's default is used.\n\nDefaultVirtualQueue=\nSpecifies the number of default virtual queue. This must be less\nthan VirtualQueue=. Defaults to unset and kernel's default is used.\n\nGenericRIO=\nTakes a boolean. It turns on the RIO-like buffering scheme.\nDefaults to unset and kernel's default is used.\n\n[FAIRQUEUEINGCONTROLLEDDELAY] SECTION OPTIONS\nThe [FairQueueingControlledDelay] section manages the queueing\ndiscipline (qdisc) of fair queuing controlled delay (FQ-CoDel).\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", \"clsact\", \"ingress\" or a class identifier. The class\nidentifier is specified as the major and minor numbers in\nhexadecimal in the range 0x1-Oxffff separated with a colon\n(\"major:minor\"). Defaults to \"root\".\n\nHandle=\nConfigures the major number of unique identifier of the qdisc,\nknown as the handle. Takes a hexadecimal number in the range\n0x1-0xffff. Defaults to unset.\n\nPacketLimit=\nSpecifies the hard limit on the real queue size. When this limit is\nreached, incoming packets are dropped. Defaults to unset and\nkernel's default is used.\n\nMemoryLimitBytes=\nSpecifies the limit on the total number of bytes that can be queued\nin this FQ-CoDel instance. When suffixed with K, M, or G, the\nspecified size is parsed as Kilobytes, Megabytes, or Gigabytes,\nrespectively, to the base of 1024. Defaults to unset and kernel's\ndefault is used.\n\nFlows=\nSpecifies the number of flows into which the incoming packets are\nclassified. Defaults to unset and kernel's default is used.\n\nTargetSec=\nTakes a timespan. Specifies the acceptable minimum\nstanding/persistent queue delay. Defaults to unset and kernel's\ndefault is used.\n\nIntervalSec=\nTakes a timespan. This is used to ensure that the measured minimum\ndelay does not become too stale. Defaults to unset and kernel's\ndefault is used.\n\nQuantumBytes=\nSpecifies the number of bytes used as the \"deficit\" in the fair\nqueuing algorithm timespan. When suffixed with K, M, or G, the\nspecified size is parsed as Kilobytes, Megabytes, or Gigabytes,\nrespectively, to the base of 1024. Defaults to unset and kernel's\ndefault is used.\n\nECN=\nTakes a boolean. This can be used to mark packets instead of\ndropping them. Defaults to unset and kernel's default is used.\n\nCEThresholdSec=\nTakes a timespan. This sets a threshold above which all packets are\nmarked with ECN Congestion Experienced (CE). Defaults to unset and\nkernel's default is used.\n\n[FAIRQUEUEING] SECTION OPTIONS\nThe [FairQueueing] section manages the queueing discipline (qdisc) of\nfair queue traffic policing (FQ).\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", \"clsact\", \"ingress\" or a class identifier. The class\nidentifier is specified as the major and minor numbers in\nhexadecimal in the range 0x1-Oxffff separated with a colon\n(\"major:minor\"). Defaults to \"root\".\n\nHandle=\nConfigures the major number of unique identifier of the qdisc,\nknown as the handle. Takes a hexadecimal number in the range\n0x1-0xffff. Defaults to unset.\n\nPacketLimit=\nSpecifies the hard limit on the real queue size. When this limit is\nreached, incoming packets are dropped. Defaults to unset and\nkernel's default is used.\n\nFlowLimit=\nSpecifies the hard limit on the maximum number of packets queued\nper flow. Defaults to unset and kernel's default is used.\n\nQuantumBytes=\nSpecifies the credit per dequeue RR round, i.e. the amount of bytes\na flow is allowed to dequeue at once. When suffixed with K, M, or\nG, the specified size is parsed as Kilobytes, Megabytes, or\nGigabytes, respectively, to the base of 1024. Defaults to unset and\nkernel's default is used.\n\nInitialQuantumBytes=\nSpecifies the initial sending rate credit, i.e. the amount of bytes\na new flow is allowed to dequeue initially. When suffixed with K,\nM, or G, the specified size is parsed as Kilobytes, Megabytes, or\nGigabytes, respectively, to the base of 1024. Defaults to unset and\nkernel's default is used.\n\nMaximumRate=\nSpecifies the maximum sending rate of a flow. When suffixed with K,\nM, or G, the specified size is parsed as Kilobits, Megabits, or\nGigabits, respectively, to the base of 1000. Defaults to unset and\nkernel's default is used.\n\nBuckets=\nSpecifies the size of the hash table used for flow lookups.\nDefaults to unset and kernel's default is used.\n\nOrphanMask=\nTakes an unsigned integer. For packets not owned by a socket, fq is\nable to mask a part of hash and reduce number of buckets associated\nwith the traffic. Defaults to unset and kernel's default is used.\n\nPacing=\nTakes a boolean, and enables or disables flow pacing. Defaults to\nunset and kernel's default is used.\n\nCEThresholdSec=\nTakes a timespan. This sets a threshold above which all packets are\nmarked with ECN Congestion Experienced (CE). Defaults to unset and\nkernel's default is used.\n\n[TRIVIALLINKEQUALIZER] SECTION OPTIONS\nThe [TrivialLinkEqualizer] section manages the queueing discipline\n(qdisc) of trivial link equalizer (teql).\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", \"clsact\", \"ingress\" or a class identifier. The class\nidentifier is specified as the major and minor numbers in\nhexadecimal in the range 0x1-Oxffff separated with a colon\n(\"major:minor\"). Defaults to \"root\".\n\nHandle=\nConfigures the major number of unique identifier of the qdisc,\nknown as the handle. Takes a hexadecimal number in the range\n0x1-0xffff. Defaults to unset.\n\nId=\nSpecifies the interface ID \"N\" of teql. Defaults to \"0\". Note that\nwhen teql is used, currently, the module schteql with\nmaxequalizers=N+1 option must be loaded before systemd-networkd is\nstarted.\n\n[HIERARCHYTOKENBUCKET] SECTION OPTIONS\nThe [HierarchyTokenBucket] section manages the queueing discipline\n(qdisc) of hierarchy token bucket (htb).\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", \"clsact\", \"ingress\" or a class identifier. The class\nidentifier is specified as the major and minor numbers in\nhexadecimal in the range 0x1-Oxffff separated with a colon\n(\"major:minor\"). Defaults to \"root\".\n\nHandle=\nConfigures the major number of unique identifier of the qdisc,\nknown as the handle. Takes a hexadecimal number in the range\n0x1-0xffff. Defaults to unset.\n\nDefaultClass=\nTakes the minor id in hexadecimal of the default class.\nUnclassified traffic gets sent to the class. Defaults to unset.\n\nRateToQuantum=\nTakes an unsigned integer. The DRR quantums are calculated by\ndividing the value configured in Rate= by RateToQuantum=.\n\n[HIERARCHYTOKENBUCKETCLASS] SECTION OPTIONS\nThe [HierarchyTokenBucketClass] section manages the traffic control\nclass of hierarchy token bucket (htb).\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", or a qdisc identifier. The qdisc identifier is specified as\nthe major and minor numbers in hexadecimal in the range 0x1-Oxffff\nseparated with a colon (\"major:minor\"). Defaults to \"root\".\n\nClassId=\nConfigures the unique identifier of the class. It is specified as\nthe major and minor numbers in hexadecimal in the range 0x1-Oxffff\nseparated with a colon (\"major:minor\"). Defaults to unset.\n\nPriority=\nSpecifies the priority of the class. In the round-robin process,\nclasses with the lowest priority field are tried for packets first.\n\nQuantumBytes=\nSpecifies how many bytes to serve from leaf at once. When suffixed\nwith K, M, or G, the specified size is parsed as Kilobytes,\nMegabytes, or Gigabytes, respectively, to the base of 1024.\n\nMTUBytes=\nSpecifies the maximum packet size we create. When suffixed with K,\nM, or G, the specified size is parsed as Kilobytes, Megabytes, or\nGigabytes, respectively, to the base of 1024.\n\nOverheadBytes=\nTakes an unsigned integer which specifies per-packet size overhead\nused in rate computations. When suffixed with K, M, or G, the\nspecified size is parsed as Kilobytes, Megabytes, or Gigabytes,\nrespectively, to the base of 1024.\n\nRate=\nSpecifies the maximum rate this class and all its children are\nguaranteed. When suffixed with K, M, or G, the specified size is\nparsed as Kilobits, Megabits, or Gigabits, respectively, to the\nbase of 1000. This setting is mandatory.\n\nCeilRate=\nSpecifies the maximum rate at which a class can send, if its parent\nhas bandwidth to spare. When suffixed with K, M, or G, the\nspecified size is parsed as Kilobits, Megabits, or Gigabits,\nrespectively, to the base of 1000. When unset, the value specified\nwith Rate= is used.\n\nBufferBytes=\nSpecifies the maximum bytes burst which can be accumulated during\nidle period. When suffixed with K, M, or G, the specified size is\nparsed as Kilobytes, Megabytes, or Gigabytes, respectively, to the\nbase of 1024.\n\nCeilBufferBytes=\nSpecifies the maximum bytes burst for ceil which can be accumulated\nduring idle period. When suffixed with K, M, or G, the specified\nsize is parsed as Kilobytes, Megabytes, or Gigabytes, respectively,\nto the base of 1024.\n\n[HEAVYHITTERFILTER] SECTION OPTIONS\nThe [HeavyHitterFilter] section manages the queueing discipline (qdisc)\nof Heavy Hitter Filter (hhf).\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", \"clsact\", \"ingress\" or a class identifier. The class\nidentifier is specified as the major and minor numbers in\nhexadecimal in the range 0x1-Oxffff separated with a colon\n(\"major:minor\"). Defaults to \"root\".\n\nHandle=\nConfigures the major number of unique identifier of the qdisc,\nknown as the handle. Takes a hexadecimal number in the range\n0x1-0xffff. Defaults to unset.\n\nPacketLimit=\nSpecifies the hard limit on the queue size in number of packets.\nWhen this limit is reached, incoming packets are dropped. An\nunsigned integer in the range 0-4294967294. Defaults to unset and\nkernel's default is used.\n\n[QUICKFAIRQUEUEING] SECTION OPTIONS\nThe [QuickFairQueueing] section manages the queueing discipline (qdisc)\nof Quick Fair Queueing (QFQ).\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", \"clsact\", \"ingress\" or a class identifier. The class\nidentifier is specified as the major and minor numbers in\nhexadecimal in the range 0x1-Oxffff separated with a colon\n(\"major:minor\"). Defaults to \"root\".\n\nHandle=\nConfigures the major number of unique identifier of the qdisc,\nknown as the handle. Takes a hexadecimal number in the range\n0x1-0xffff. Defaults to unset.\n\n[QUICKFAIRQUEUEINGCLASS] SECTION OPTIONS\nThe [QuickFairQueueingClass] section manages the traffic control class\nof Quick Fair Queueing (qfq).\n\nParent=\nConfigures the parent Queueing Discipline (qdisc). Takes one of\n\"root\", or a qdisc identifier. The qdisc identifier is specified as\nthe major and minor numbers in hexadecimal in the range 0x1-Oxffff\nseparated with a colon (\"major:minor\"). Defaults to \"root\".\n\nClassId=\nConfigures the unique identifier of the class. It is specified as\nthe major and minor numbers in hexadecimal in the range 0x1-Oxffff\nseparated with a colon (\"major:minor\"). Defaults to unset.\n\nWeight=\nSpecifies the weight of the class. Takes an integer in the range\n1...1023. Defaults to unset in which case the kernel default is\nused.\n\nMaxPacketBytes=\nSpecifies the maximum packet size in bytes for the class. When\nsuffixed with K, M, or G, the specified size is parsed as\nKilobytes, Megabytes, or Gigabytes, respectively, to the base of\n1024. When unset, the kernel default is used.\n\n[BRIDGEVLAN] SECTION OPTIONS\nThe [BridgeVLAN] section manages the VLAN ID configuration of a bridge\nport and accepts the following keys. Specify several [BridgeVLAN]\nsections to configure several VLAN entries. The VLANFiltering= option\nhas to be enabled, see the [Bridge] section in systemd.netdev(5).\n\nVLAN=\nThe VLAN ID allowed on the port. This can be either a single ID or\na range M-N. VLAN IDs are valid from 1 to 4094.\n\nEgressUntagged=\nThe VLAN ID specified here will be used to untag frames on egress.\nConfiguring EgressUntagged= implicates the use of VLAN= above and\nwill enable the VLAN ID for ingress as well. This can be either a\nsingle ID or a range M-N.\n\nPVID=\nThe Port VLAN ID specified here is assigned to all untagged frames\nat ingress. PVID= can be used only once. Configuring PVID=\nimplicates the use of VLAN= above and will enable the VLAN ID for\ningress as well.\n", "subsections": [] }, "EXAMPLES": { "content": "Example 1. Static network configuration\n\n# /etc/systemd/network/50-static.network\n[Match]\nName=enp2s0\n\n[Network]\nAddress=192.168.0.15/24\nGateway=192.168.0.1\n\nThis brings interface \"enp2s0\" up with a static address. The specified\ngateway will be used for a default route.\n\nExample 2. DHCP on ethernet links\n\n# /etc/systemd/network/80-dhcp.network\n[Match]\nName=en*\n\n[Network]\nDHCP=yes\n\nThis will enable DHCPv4 and DHCPv6 on all interfaces with names\nstarting with \"en\" (i.e. ethernet interfaces).\n\nExample 3. IPv6 Prefix Delegation\n\n# /etc/systemd/network/55-ipv6-pd-upstream.network\n[Match]\nName=enp1s0\n\n[Network]\nDHCP=ipv6\n\n# /etc/systemd/network/56-ipv6-pd-downstream.network\n[Match]\nName=enp2s0\n\n[Network]\nIPv6SendRA=yes\nDHCPv6PrefixDelegation=yes\n\nThis will enable DHCPv6-PD on the interface enp1s0 as an upstream\ninterface where the DHCPv6 client is running and enp2s0 as a downstream\ninterface where the prefix is delegated to. The delegated prefixes are\ndistributed by IPv6 Router Advertisement on the downstream network.\n\nExample 4. A bridge with two enslaved links\n\n# /etc/systemd/network/25-bridge-static.network\n[Match]\nName=bridge0\n\n[Network]\nAddress=192.168.0.15/24\nGateway=192.168.0.1\nDNS=192.168.0.1\n\n# /etc/systemd/network/25-bridge-slave-interface-1.network\n[Match]\nName=enp2s0\n\n[Network]\nBridge=bridge0\n\n# /etc/systemd/network/25-bridge-slave-interface-2.network\n[Match]\nName=wlp3s0\n\n[Network]\nBridge=bridge0\n\nThis creates a bridge and attaches devices \"enp2s0\" and \"wlp3s0\" to it.\nThe bridge will have the specified static address and network assigned,\nand a default route via the specified gateway will be added. The\nspecified DNS server will be added to the global list of DNS resolvers.\n\nExample 5. Bridge port with VLAN forwarding\n\n# /etc/systemd/network/25-bridge-slave-interface-1.network\n[Match]\nName=enp2s0\n\n[Network]\nBridge=bridge0\n\n[BridgeVLAN]\nVLAN=1-32\nPVID=42\nEgressUntagged=42\n\n[BridgeVLAN]\nVLAN=100-200\n\n[BridgeVLAN]\nEgressUntagged=300-400\n\nThis overrides the configuration specified in the previous example for\nthe interface \"enp2s0\", and enables VLAN on that bridge port. VLAN IDs\n1-32, 42, 100-400 will be allowed. Packets tagged with VLAN IDs 42,\n300-400 will be untagged when they leave on this interface. Untagged\npackets which arrive on this interface will be assigned VLAN ID 42.\n\nExample 6. Various tunnels\n\n/etc/systemd/network/25-tunnels.network\n[Match]\nName=ens1\n\n[Network]\nTunnel=ipip-tun\nTunnel=sit-tun\nTunnel=gre-tun\nTunnel=vti-tun\n\n/etc/systemd/network/25-tunnel-ipip.netdev\n[NetDev]\nName=ipip-tun\nKind=ipip\n\n/etc/systemd/network/25-tunnel-sit.netdev\n[NetDev]\nName=sit-tun\nKind=sit\n\n/etc/systemd/network/25-tunnel-gre.netdev\n[NetDev]\nName=gre-tun\nKind=gre\n\n/etc/systemd/network/25-tunnel-vti.netdev\n[NetDev]\nName=vti-tun\nKind=vti\n\nThis will bring interface \"ens1\" up and create an IPIP tunnel, a SIT\ntunnel, a GRE tunnel, and a VTI tunnel using it.\n\nExample 7. A bond device\n\n# /etc/systemd/network/30-bond1.network\n[Match]\nName=bond1\n\n[Network]\nDHCP=ipv6\n\n# /etc/systemd/network/30-bond1.netdev\n[NetDev]\nName=bond1\nKind=bond\n\n# /etc/systemd/network/30-bond1-dev1.network\n[Match]\nMACAddress=52:54:00:e9:64:41\n\n[Network]\nBond=bond1\n\n# /etc/systemd/network/30-bond1-dev2.network\n[Match]\nMACAddress=52:54:00:e9:64:42\n\n[Network]\nBond=bond1\n\nThis will create a bond device \"bond1\" and enslave the two devices with\nMAC addresses 52:54:00:e9:64:41 and 52:54:00:e9:64:42 to it. IPv6 DHCP\nwill be used to acquire an address.\n\nExample 8. Virtual Routing and Forwarding (VRF)\n\nAdd the \"bond1\" interface to the VRF master interface \"vrf1\". This will\nredirect routes generated on this interface to be within the routing\ntable defined during VRF creation. For kernels before 4.8 traffic won't\nbe redirected towards the VRFs routing table unless specific ip-rules\nare added.\n\n# /etc/systemd/network/25-vrf.network\n[Match]\nName=bond1\n\n[Network]\nVRF=vrf1\n\nExample 9. MacVTap\n\nThis brings up a network interface \"macvtap-test\" and attaches it to\n\"enp0s25\".\n\n# /lib/systemd/network/25-macvtap.network\n[Match]\nName=enp0s25\n\n[Network]\nMACVTAP=macvtap-test\n\nExample 10. A Xfrm interface with physical underlying device.\n\n# /etc/systemd/network/27-xfrm.netdev\n[NetDev]\nName=xfrm0\nKind=xfrm\n\n[Xfrm]\nInterfaceId=7\n\n# /etc/systemd/network/27-eth0.network\n[Match]\nName=eth0\n\n[Network]\nXfrm=xfrm0\n\nThis creates a \"xfrm0\" interface and binds it to the \"eth0\" device.\nThis allows hardware based ipsec offloading to the \"eth0\" nic. If\noffloading is not needed, xfrm interfaces can be assigned to the \"lo\"\ndevice.\n", "subsections": [] }, "SEE ALSO": { "content": "systemd(1), systemd-networkd.service(8), systemd.link(5),\nsystemd.netdev(5), systemd-resolved.service(8)\n", "subsections": [] }, "NOTES": { "content": "1. RFC 7217\nhttps://tools.ietf.org/html/rfc7217\n\n2. Link-Local Multicast Name Resolution\nhttps://tools.ietf.org/html/rfc4795\n\n3. Multicast DNS\nhttps://tools.ietf.org/html/rfc6762\n\n4. DNS-over-TLS\nhttps://tools.ietf.org/html/rfc7858\n\n5. DNSSEC\nhttps://tools.ietf.org/html/rfc4033\n\n6. IEEE 802.1AB-2016\nhttps://standards.ieee.org/findstds/standard/802.1AB-2016.html\n\n7. ip-sysctl.txt\nhttps://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt\n\n8. RFC 4941\nhttps://tools.ietf.org/html/rfc4941\n\n9. RFC 1027\nhttps://tools.ietf.org/html/rfc1027\n\n10. RFC 6275\nhttps://tools.ietf.org/html/rfc6275\n\n11. RFC 5227\nhttps://tools.ietf.org/html/rfc5227\n\n12. RFC 4862\nhttps://tools.ietf.org/html/rfc4862\n\n13. RFC 3041\nhttps://tools.ietf.org/html/rfc3041\n\n14. RFC 3484\nhttps://tools.ietf.org/html/rfc3484\n\n15. RFC 4191\nhttps://tools.ietf.org/html/rfc4191\n\n16. RFC 8520\nhttps://tools.ietf.org/html/rfc8520\n\n17. RFC 7844\nhttps://tools.ietf.org/html/rfc7844\n\n18. C-style escapes\nhttps://en.wikipedia.org/wiki/EscapesequencesinC#Tableofescapesequences\n\n19. RFC 7084\nhttps://tools.ietf.org/html/rfc7084\n\n20. RFC 3315\nhttps://tools.ietf.org/html/rfc3315#section-17.2.1\n\n21. RFC 4291\nhttps://tools.ietf.org/html/rfc4291#section-2.5.4\n\n22. RFC 1542\nhttps://tools.ietf.org/html/rfc1542\n\n23. RFC 4861\nhttps://tools.ietf.org/html/rfc4861\n\nsystemd 249 SYSTEMD.NETWORK(5)", "subsections": [] } } } }