# ip-tunnel(8) - man - phpMan

[IP-TUNNEL(8)](https://www.chedong.com/phpMan.php/man/IP-TUNNEL/8/markdown)                                    Linux                                   [IP-TUNNEL(8)](https://www.chedong.com/phpMan.php/man/IP-TUNNEL/8/markdown)



## NAME
       ip-tunnel - tunnel configuration

## SYNOPSIS
### ip tunnel help

       **ip** [ _OPTIONS_ ] **tunnel** { **add** | **change** | **del** | **show** | **prl** | **6rd** } [ _NAME_ ]
               [ **mode** _MODE_ ] [ **remote** _ADDR_ ] [ **local** _ADDR_ ]
               [ [**i**|**o**]**seq** ] [ [**i**|**o**]**key** _KEY_ ] [ [**i**|**o**]**csum** ] ]
               [ **encaplimit** _ELIM_ ] [ **ttl**|**hoplimit** _TTL_ ]
               [ **tos** _TOS_ ] [ **flowlabel** _FLOWLABEL_ ]
               [ **prl-default** _ADDR_ ] [ **prl-nodefault** _ADDR_ ] [ **prl-delete** _ADDR_ ]
               [ **6rd-prefix** _ADDR_ ] [ **6rd-relay**___**prefix** _ADDR_ ] [ **6rd-reset** ]
               [ [**no**]**pmtudisc** ] [ [**no**]**ignore-df** ] [ [**no**]**allow-localremote** ]
               [ **dev** _PHYS_DEV_ ]

       _MODE_ :=  { **ipip** | **gre** | **sit** | **isatap** | **vti** | **ip6ip6** | **ipip6** | **ip6gre** | **vti6** | **any** }

       _ADDR_ := { _IP_ADDRESS_ | **any** }

       _TOS_ := { _STRING_ | _00_.._ff_ | **inherit** | **inherit/**_STRING_ | **inherit/**_00_**..**_ff_ }

       _ELIM_ := { **none** | _0_.._255_ }

       _TTL_ := { _1_.._255_ | **inherit** }

       _KEY_ := { _DOTTED_QUAD_ | _NUMBER_ }


## DESCRIPTION
       **tunnel** objects are tunnels, encapsulating packets in IP packets and then sending them over
       the IP infrastructure.  The encapsulating (or outer) address family is specified by the **-f**
       option. The default is IPv4.


### ip tunnel add
              add a new tunnel

### ip tunnel change
              change an existing tunnel

### ip tunnel delete
              destroy a tunnel

              **name** _NAME_ **(default)**
                     select the tunnel device name.


              **mode** _MODE_
                     set the tunnel mode. Available modes depend on the encapsulating address fam‐
                     ily.
                     Modes for IPv4 encapsulation available: **ipip**, **sit**, **isatap**, **vti**, and **gre**.
                     Modes for IPv6 encapsulation available: **ip6ip6**, **ipip6**, **ip6gre**, **vti6**, and **any**.


              **remote** _ADDRESS_
                     set the remote endpoint of the tunnel.


              **local** _ADDRESS_
                     set the fixed local address for tunneled packets.  It must be an address on an‐
                     other interface of this host.


              **ttl** _N_

              **hoplimit** _N_
                     set a fixed TTL (IPv4) or hoplimit (IPv6) _N_ on tunneled packets.  _N_ is a number
                     in the range 1--255. 0 is a special value meaning that packets inherit the TTL
                     value.  The default value for IPv4 tunnels is: **inherit**.  The default value for
                     IPv6 tunnels is: **64**.



              **tos** _T_

              **dsfield** _T_

              **tclass** _T_
                     set the type of service (IPv4) or traffic class (IPv6) field on tunneled pack‐
                     ets, which can be specified as either a two-digit hex value (e.g. c0) or a pre‐
                     defined string (e.g. internet).  The value **inherit** causes the field to be
                     copied from the original IP header. The values **inherit/**_STRING_ or **inherit/**_00_**..**_ff_
                     will set the field to _STRING_ or _00_.._ff_ when tunneling non-IP packets. The de‐
                     fault value is 00.


              **dev** _NAME_
                     bind the tunnel to the device _NAME_ so that tunneled packets will only be routed
                     via this device and will not be able to escape to another device when the route
                     to endpoint changes.


              **nopmtudisc**
                     disable Path MTU Discovery on this tunnel.  It is enabled by default. Note that
                     a fixed ttl is incompatible with this option: tunneling with a fixed ttl always
                     makes pmtu discovery.


              **ignore-df**
                     enable IPv4 DF suppression on this tunnel.  Normally datagrams that exceed the
                     MTU will be fragmented; the presence of the DF flag inhibits this, resulting
                     instead in an ICMP Unreachable (Fragmentation Required) message.  Enabling this
                     attribute causes the DF flag to be ignored.


              **key** _K_

              **ikey** _K_

              **okey** _K_ ( **only** **GRE** **tunnels** ) use keyed GRE with key _K_. _K_ is either a number or an IP
                     address-like dotted quad.  The **key** parameter sets the key to use in both direc‐
                     tions.  The **ikey** and **okey** parameters set different keys for input and output.


              **csum**, **icsum**, **ocsum**
                     ( **only** **GRE** **tunnels** ) generate/require checksums for tunneled packets.  The **oc**‐‐
                     **sum** flag calculates checksums for outgoing packets.  The **icsum** flag requires
                     that all input packets have the correct checksum. The **csum** flag is equivalent
                     to the combination **icsum** **ocsum**.


              **seq**, **iseq**, **oseq**
                     ( **only** **GRE** **tunnels** ) serialize packets.  The **oseq** flag enables sequencing of
                     outgoing packets.  The **iseq** flag requires that all input packets are serial‐
                     ized.  The **seq** flag is equivalent to the combination **iseq** **oseq**.  **It** **doesn't**
                     **work.** **Don't** **use** **it.**


              **encaplimit** _ELIM_
                     ( **only** **IPv6** **tunnels** ) set a fixed encapsulation limit. Default is 4.


              **flowlabel** _FLOWLABEL_
                     ( **only** **IPv6** **tunnels** ) set a fixed flowlabel.


              **allow-localremote**
                     ( **only** **IPv6** **tunnels** ) allow remote endpoint on the local host.


### ip tunnel prl
              potential router list (ISATAP only)

              **dev** _NAME_
                     mandatory device name.


              **prl-default** _ADDR_

              **prl-nodefault** _ADDR_

              **prl-delete** _ADDR_
                     Add or delete **ADDR** as a potential router or default router.


### ip tunnel show
              list tunnels This command has no arguments.


## SEE ALSO
       [**ip**(8)](https://www.chedong.com/phpMan.php/man/ip/8/markdown)


## AUTHOR
       Original Manpage by Michail Litvak <<mci@owl.openwall.com>>



iproute2                                     20 Dec 2011                                [IP-TUNNEL(8)](https://www.chedong.com/phpMan.php/man/IP-TUNNEL/8/markdown)