On Apache/1.3.41 (Unix) PHP/5.2.5 mod_perl/1.30 mod_gzip/1.3.26.1a
Under GNU General Public License
2009-01-09 07:09 @38.103.63.58 CrawledBy CCBot/1.0 (+http://www.commoncrawl.org/bot.html)
IPPPD(8) Linux System Administration IPPPD(8)
NAME
ipppd - (ISDN) Point to Point Protocol daemon
SYNOPSIS
/usr/sbin/ipppd [ options ] [ device ]
DESCRIPTION
The Point-to-Point Protocol (PPP) provides a method for transmitting datagrams over
serial point-to-point links. PPP is composed of three parts: a method for encapsu-
lating datagrams over serial links, an extensible Link Control Protocol (LCP), and
a family of Network Control Protocols (NCP) for establishing and configuring dif-
ferent network-layer protocols.
The encapsulation scheme is provided by driver code in the kernel. ipppd provides
the basic LCP, authentication support, and an NCP for establishing and configuring
the Internet Protocol (IP) (called the IP Control Protocol, IPCP).
NOTES for (ISDN) IPPPD
This special (ISDN) PPP daemon is a modified version of pppd and provides syn-
chronous PPP for ISDN connections.
If you need asynchronous PPP over ISDN lines use pppd instead with the ISDN charac-
ter devices, see ttyI(4).
The ipppd can handle multiple devices. This is necessary to link several connec-
tions together to one bundle. ipppd should be started once. It opens the devices
and waits for connections. If the connections is closed ipppd reopens the device
automatically (the device, that’s it ... not the link to the remote). So you
shouldn’t kill the ipppd to close a link. Instead, trigger a hangup on the netde-
vice layer by ’isdnctrl hangup <device>’.
The facility to configure the daemon via file /etc/ppp/ioptions.<devname> is dis-
abled. The ’file’ option or the command line may be used for individual configura-
tion.
Do not set the permissions of the program to ’setuid to root on execution’. Call
the daemon as root instead. No common user should have the need to call the dae-
mon!
OPTIONS
<device>
Communicate over the named device. The string "/dev/" is prepended if nec-
essary. If no device name is given, or if the name of the controlling ter-
minal is given, ipppd will use the controlling terminal, and will not fork
to put itself in the background.
<local_IP_address>:<remote_IP_address>
Set the local and/or remote interface IP addresses. Either one may be omit-
ted. The IP addresses can be specified with a host name or in decimal dot
notation (e.g. 150.234.56.78). The default local address is the (first) IP
address of the system (unless the noipdefault option is given). The remote
address will be obtained from the peer if not specified in any option.
Thus, in simple cases, this option is not required. If a local and/or
remote IP address is specified with this option, ipppd will not accept a
different value from the peer in the IPCP negotiation, unless the ipcp-
accept-local and/or ipcp-accept-remote options are given, respectively.
active-filter filter-expression
Specifies a packet filter to be applied to data packets to determine which
packets are to be regarded as link activity, and therefore reset the idle
timer, or cause the link to be brought up in demand-dialling mode. This
option is useful in conjunction with the idle option if there are packets
being sent or received regularly over the link (for example, routing infor-
mation packets) which would otherwise prevent the link from ever appearing
to be idle. The filter-expression syntax is as described for tcpdump(1),
except that qualifiers which are inappropriate for a PPP link, such as ether
and arp, are not permitted. Generally the filter expression should be
enclosed in single-quotes to prevent whitespace in the expression from being
interpreted by the shell. This option is currently only available if both
the kernel and ipppd were compiled with IPPP_FILTER defined.
-ac Disable Address/Control compression negotiation (use default, i.e.
address/control field compression disabled).
-all Don’t request or allow negotiation of any options for LCP and IPCP (use
default values).
auth Require the peer to authenticate itself before allowing network packets to
be sent or received.
bsdcomp nr,nt
Request that the peer compress packets that it sends, using the BSD-Compress
scheme, with a maximum code size of nr bits, and agree to compress packets
sent to the peer with a maximum code size of nt bits. If nt is not speci-
fied, it defaults to the value given for nr. Values in the range 9 to 15
may be used for nr and nt; larger values give better compression but consume
more kernel memory for compression dictionaries. Alternatively, a value of
0 for nr or nt disables compression in the corresponding direction.
-bsdcomp
Disables compression; ipppd will not request or agree to compress packets
using the BSD-Compress scheme.
callback <string>
Request the peer to call back at the location given in <string>. Ususally
this is a phone number, but it may be interpreted differently (or ignored)
depending on the callback-type option. If <string> is the empty string,
ipppd automatically tries to negotiate a callback type that does not need a
location to be specified.
callback-delay <n>
Callback delay for CBCP in seconds. If callback is negotiated using CBCP,
request that the peer waits at least <n> seconds before calling back.
Ignored if callback is negotiated as specified in RFC 1570. Legal range is
0..255, default is 5.
callback-cbcp
Enable callback negotiation via CBCB (default).
-callback-cbcp
Disable callback negotiation via CBCB.
no-callback-cbcp
Disable callback negotiation via CBCB.
callback-cbcp-preferred
If both CBCP and RFC 1570 style callback negotiation is enabled, CBCP is
preferred (default)
callback-rfc1570-preferred
If both CBCP and RFC 1570 style callback negotiation is enabled, RFC 1570
style is preferred.
callback-rfc1570
Enable RFC 1570 style callback negotiation (default).
-callback-rfc1570
Disable RFC 1570 style callback negotiation.
no-callback-rfc1570
Disable RFC 1570 style callback negotiation (default).
callback-type <n>
Specifies how to interpret the location identifier given as parameter of the
callback option. Legal values are 0..4. A value of 0 means that only call-
back types should be negotiated that need no extra location id. No location
id is sent to the peer in this case. For RFC 1570 style callback negotia-
tion, the values 1..4 indicate how the peer should interpret the location
identifier: 1 - id is a system specific dial string, 2 - id is used for
database lookup by the peer, 3 - id is a phone number, and 4 id is a name.
For CBCP callback negotiation, the location id is always interpreted as a
phone number.
-ccp Necessary for a few netblazers on the remote side.
noccp same as -ccp
+chap Require the peer to authenticate itself using CHAP [Cryptographic Handshake
Authentication Protocol] authentication.
-chap Don’t agree to authenticate using CHAP.
chap-interval <n>
If this option is given, ipppd will rechallenge the peer every <n> seconds.
chap-max-challenge <n>
Set the maximum number of CHAP challenge transmissions to <n> (default 10).
chap-restart <n>
Set the CHAP restart interval (retransmission timeout for challenges) to <n>
seconds (default 3).
debug Increase debugging level (same as -d). If this option is given, ipppd will
log the contents of all control packets sent or received in a readable form.
The packets are logged through syslog with facility daemon and level debug.
This information can be directed to a file by setting up /etc/syslog.conf
appropriately (see syslog.conf(5)).
-d Increase debugging level (same as the debug option).
defaultroute
Add a default route to the system routing tables, using the peer as the
gateway, when IPCP negotiation is successfully completed. This entry is
removed when the PPP connection is broken.
-defaultroute
Disable the defaultroute option. The system administrator who wishes to
prevent users from creating default routes with ipppd can do so by placing
this option in the /etc/ppp/ioptions file.
deldefaultroute
Replace default route if it already exists. Together with the option
defaultroute, this will replace any existing default route by a new one
through this ipppd’s interface when it comes up.
-detach
Don’t fork to become a background process (otherwise ipppd will do so if a
serial device other than its controlling terminal is specified).
domain <d>
Append the domain name <d> to the local host name for authentication pur-
poses. For example, if gethostname() returns the name porsche, but the
fully qualified domain name is porsche.Quotron.COM, you would use the domain
option to set the domain name to Quotron.COM.
file <f>
Read options from file <f> (the format is described below).
-ip Disable IP address negotiation. If this option is used, the remote IP
address must be specified with an option on the command line or in an
options file.
+ip-protocol
Enable the IPCP and IP protocols. This is the default condition. This option
is only needed if the default setting is -ip-protocol.
-ip-protocol
Disable the IPCP and IP protocols. This should only be used if you know that
you are using a client which only understands IPX and you don’t want to con-
fuse the client with the IPCP protocol.
+ipx-protocol
Enable the IPXCP and IPX protocols. This is the default condition if your
kernel supports IPX. This option is only needed if the default setting is
-ipx-protocol. If your kernel does not support IPX then this option will
have no effect.
-ipx-protocol
Disable the IPXCP and IPX protocols. This should only be used if you know
that you are using a client which only understands IP and you don’t want to
confuse the client with the IPXCP protocol.
ipcp-accept-local
With this option, ipppd will accept the peer’s idea of our local IP address,
even if the local IP address was specified in an option.
ipcp-accept-remote
With this option, ipppd will accept the peer’s idea of its (remote) IP
address, even if the remote IP address was specified in an option.
ipcp-max-configure <n>
Set the maximum number of IPCP configure-request transmissions to <n>
(default 10).
ipcp-max-failure <n>
Set the maximum number of IPCP configure-NAKs returned before starting to
send configure-Rejects instead to <n> (default 10).
ipcp-max-terminate <n>
Set the maximum number of IPCP terminate-request transmissions to <n>
(default 3).
ipcp-restart <n>
Set the IPCP restart interval (retransmission timeout) to <n> seconds
(default 3).
ipparam string
Provides an extra parameter to the ip-up and ip-down scripts. If this
option is given, the string supplied is given as the 6th parameter to those
scripts.
ipx-network <n>
Set the IPX network number in the IPXCP configure request frame to <n>.
There is no valid default. If this option is not specified then the network
number is obtained from the peer. If the peer does not have the network num-
ber, the IPX protocol will not be started. This is a hexadecimal number and
is entered without any leading sequence such as 0x. It is related to the
ipxcp-accept-network option.
ipx-node <n>:<m>
Set the IPX node numbers. The two node numbers are separated from each other
with a colon character. The first number <n> is the local node number. The
second number <m> is the peer’s node number. Each node number is a hexadeci-
mal number, to the maximum of ten significant digits. The node numbers on
the ipx-network must be unique. There is no valid default. If this option is
not specified then the node number is obtained from the peer. This option is
a related to the ipxcp-accept-local and ipxcp-accept-remote options.
ipx-router-name <string>
Set the name of the router. This is a string and is sent to the peer as
information data.
ipx-routing <n>
Set the routing protocol to be received by this option. Use a comma-serper-
ated list if you want to specify more than one protocol. The ’none’ option
(0) may be specified as the only instance of ipx-routing. The values may be
0 for NONE, 2 for RIP/SAP, and 4 for NLSP.
ipxcp-accept-local
Accept the peer’s NAK for the node number specified in the ipx-node option.
If a node number was specified, and non-zero, the default is to insist that
the value be used. If you include this option then you will permit the peer
to override the entry of the node number.
ipxcp-accept-network
Accept the peer’s NAK for the network number specified in the ipx-network
option. If a network number was specified, and non-zero, the default is to
insist that the value be used. If you include this option then you will per-
mit the peer to override the entry of the node number.
ipxcp-accept-remote
Use the peer’s network number specified in the configure request frame. If a
node number was specified for the peer and this option was not specified,
the peer will be forced to use the value which you have specified.
ipxcp-max-configure <n>
Set the maximum number of IPXCP configure request frames which the system
will send to <n>. The default is 10.
ipxcp-max-failure <n>
Set the maximum number of IPXCP NAK frames which the local system will send
before it rejects the options. The default value is 3.
ipxcp-max-terminate <n>
Set the maximum nuber of IPXCP terminate request frames before the local
system considers that the peer is not listening to them. The default value
is 3.
kdebug n
Enable debugging code in the kernel-level PPP driver. The argument n is a
number which is the sum of the following values: 1 to enable general debug
messages, 2 to request that the contents of received packets be printed, and
4 to request that the contents of transmitted packets be printed.
lcp-echo-failure <n>
If this option is given, ipppd will presume the peer to be dead if n LCP
echo-requests are sent without receiving a valid LCP echo-reply. If this
happens, ipppd will terminate the connection. Use of this option requires a
non-zero value for the lcp-echo-interval parameter. This option can be used
to enable ipppd to terminate after the physical connection has been broken
(e.g., the line hung up) in situations where no hardware modem control lines
are available.
lcp-echo-interval <n>
If this option is given, ipppd will send an LCP echo-request frame to the
peer every n seconds. With Linux, the echo-request is sent when no packets
have been received from the peer for n seconds. Normally the peer should
respond to the echo-request by sending an echo-reply. This option can be
used with the lcp-echo-failure option to detect that the peer is no longer
connected.
lcp-max-configure <n>
Set the maximum number of LCP configure-request transmissions to <n>
(default 10).
lcp-max-failure <n>
Set the maximum number of LCP configure-NAKs returned before starting to
send configure-Rejects instead to <n> (default 10).
lcp-max-terminate <n>
Set the maximum number of LCP terminate-request transmissions to <n>
(default 3).
lcp-restart <n>
Set the LCP restart interval (retransmission timeout) to <n> seconds
(default 3).
lock Specifies that ipppd should create a UUCP-style lock file for the serial
device to ensure exclusive access to the device.
login Use the system password database for authenticating the peer using PAP, and
record the user in the system wtmp file.
-mn Disable magic number negotiation. With this option, ipppd cannot detect a
looped-back line.
+mp enables MPPP negotiation
mru <n>
Set the MRU [Maximum Receive Unit] value to <n> for negotiation. ipppd will
ask the peer to send packets of no more than <n> bytes. The minimum MRU
value is 128. The default MRU value is 1500. A value of 296 is recommended
for slow links (40 bytes for TCP/IP header + 256 bytes of data).
-mru Disable MRU [Maximum Receive Unit] negotiation. With this option, ipppd
will use the default MRU value of 1500 bytes.
ms-dns <n>
This option sets the IP address or addresses for the Domain Name Server. It
is used by Microsoft Windows clients. The primary DNS address is specified
by the first instance of the ms-dns option. The secondary is specified by
the second instance.
ms-get-dns
Implements the client side of RFC1877. If ipppd is acting as a client to a
server that implements RFC1877 such as one intended to be used with
Microsoft Windows clients, this option allows ipppd to obtain one or two DNS
(Domain Name Server) addresses from the server. It does not do anything
with these addresses except put them in the environment (MS_DNS1 MS_DNS2)
that is passed to scripts. For compatibility with the async pppd, DNS1 DNS2
environment variables are also set. A sample resolv.conf is created in
/etc/ppp/resolv.conf. The /etc/ppp/ip-up script should use this information
to perform whatever adjustment is necessary. Note: RFC1877 is a horrible
protocol layering violation, the correct approach would be to use DHCP after
the IPCP phase.
ms-get-wins
As ms-get-dns but for WINS (Windows Internet Name Services) server
addresses. Environment variables are MS_WINS1 and MS_WINS2.
mtu <n>
Set the MTU [Maximum Transmit Unit] value to <n>. Unless the peer requests
a smaller value via MRU negotiation, ipppd will request that the kernel net-
working code send data packets of no more than n bytes through the PPP net-
work interface.
name <n>
Set the name of the local system for authentication purposes to <n>.
netmask <n>
Set the interface netmask to <n>, a 32 bit netmask in "decimal dot" notation
(e.g. 255.255.255.0). If this option is given, the value specified is ORed
with the default netmask. The default netmask is chosen based on the nego-
tiated remote IP address; it is the appropriate network mask for the class
of the remote IP address, ORed with the netmasks for any non point-to-point
network interfaces in the system which are on the same network.
noipdefault
Disables the default behaviour when no local IP address is specified, which
is to determine (if possible) the local IP address from the hostname. With
this option, the peer will have to supply the local IP address during IPCP
negotiation (unless it specified explicitly on the command line or in an
options file).
passive
Enables the "passive" option in the LCP. With this option, ipppd will
attempt to initiate a connection; if no reply is received from the peer,
ipppd will then just wait passively for a valid LCP packet from the peer
(instead of exiting, as it does without this option).
-p Same as the passive option.
+pap Require the peer to authenticate itself using PAP.
-pap Don’t agree to authenticate using PAP.
papcrypt
Indicates that all secrets in the /etc/ppp/pap-secrets file which are used
for checking the identity of the peer are encrypted, and thus ipppd should
not accept a password which (before encryption) is identical to the secret
from the /etc/ppp/pap-secrets file.
pap-max-authreq <n>
Set the maximum number of PAP authenticate-request transmissions to <n>
(default 10).
pap-restart <n>
Set the PAP restart interval (retransmission timeout) to <n> seconds
(default 3).
pap-timeout <n>
Set the maximum time that ipppd will wait for the peer to authenticate
itself with PAP to <n> seconds (0 means no limit).
pass-filter filter-expression
Specifies a packet filter to applied to data packets being sent or received
to determine which packets should be allowed to pass. Packets which are
rejected by the filter are silently discarded. This option can be used to
prevent specific network daemons (such as routed) using up link bandwidth,
or to provide a basic firewall capability. The filter-expression syntax is
as described for tcpdump(1), except that qualifiers which are inappropriate
for a PPP link, such as ether and arp, are not permitted. Generally the fil-
ter expression should be enclosed in single-quotes to prevent whitespace in
the expression from being interpreted by the shell. Note that it is possible
to apply different constraints to incoming and outgoing packets using the
inbound and outbound qualifiers. This option is currently only available if
both the kernel and ipppd were compiled with IPPP_FILTER defined.
-pc Disable protocol field compression negotiation (use default, i.e. protocol
field compression disabled).
pidfile <filename>
Use <filename> instead of /var/run/ipppd.pid
pred1comp
Attempt to request that the peer send the local system frames which have
been compressed by the Predictor-1 compression. The compression protocols
must be loaded or this option will be ignored.
-pred1comp
Do not accept Predictor-1 comprssion, even if the peer wants to send this
type of compression and support has been defined in the kernel.
proxyarp
Add an entry to this system’s ARP [Address Resolution Protocol] table with
the IP address of the peer and the Ethernet address of this system.
-proxyarp
Disable the proxyarp option. The system administrator who wishes to prevent
users from creating proxy ARP entries with ipppd can do so by placing this
option in the /etc/ppp/ioptions file.
remotename <n>
Set the assumed name of the remote system for authentication purposes to
<n>.
set_userip
You may define valid IPs in /etc/ppp/useriptab
silent With this option, ipppd will not transmit LCP packets to initiate a connec-
tion until a valid LCP packet is received from the peer (as for the ‘pas-
sive’ option with ancient versions of ipppd).
+ua <p>
Agree to authenticate using PAP [Password Authentication Protocol] if
requested by the peer, and use the data in file <p> for the user and pass-
word to send to the peer. The file contains the remote user name, followed
by a newline, followed by the remote password, followed by a newline. This
option is obsolescent.
usefirstip
Gets the remote address from the first entry in the auth file (if there is
an IP address entry). This address should be a full IP address not an
address from a masked area. Ipppd calls ’gethostbyname()’ and negotiates
the result. IP from auth file will overwrite the remote address gotten from
the interface. ’usefirstip’ is UNTESTED!
usehostname
Enforce the use of the hostname as the name of the local system for authen-
tication purposes (overrides the name option).
usepeerdns
Same as ms-get-dns for compatibility with async pppd.
user <u>
Set the user name to use for authenticating this machine with the peer using
PAP to <u>.
useifip
will get (if not set to 0.0.0.0) the IP address for the negotiation from the
attached network-interface. (also: ipppd will try to negotiate ’pointo-
point’ IP as remote IP) interface address -> local IP pointopoint address ->
remote IP
-vj Disable negotiation of Van Jacobson style TCP/IP header compression (use
default, i.e. no compression).
-vjccomp
Disable the connection-ID compression option in Van Jacobson style TCP/IP
header compression. With this option, ipppd will not omit the connection-ID
byte from Van Jacobson compressed TCP/IP headers, nor ask the peer to do so.
vj-max-slots n
Sets the number of connection slots to be used by the Van Jacobson TCP/IP
header compression and decompression code to n, which must be between 2 and
16 (inclusive).
OPTIONS FILES
Options can be taken from files as well as the command line. ipppd reads options
from the file /etc/ppp/ioptions before looking at the command line. An options
file is parsed into a series of words, delimited by whitespace. Whitespace can be
included in a word by enclosing the word in quotes ("). A backslash (\) quotes the
following character. A hash (#) starts a comment, which continues until the end of
the line.
AUTHENTICATION
ipppd provides system administrators with sufficient access control that PPP access
to a server machine can be provided to legitimate users without fear of compromis-
ing the security of the server or the network it’s on. In part this is provided by
the /etc/ppp/ioptions file, where the administrator can place options to require
authentication whenever ipppd is run, and in part by the PAP and CHAP secrets
files, where the administrator can restrict the set of IP addresses which individ-
ual users may use.
The default behaviour of ipppd is to agree to authenticate if requested, and to not
require authentication from the peer. However, ipppd will not agree to authenti-
cate itself with a particular protocol if it has no secrets which could be used to
do so.
Authentication is based on secrets, which are selected from secrets files
(/etc/ppp/pap-secrets for PAP, /etc/ppp/chap-secrets for CHAP). Both secrets files
have the same format, and both can store secrets for several combinations of server
(authenticating peer) and client (peer being authenticated). Note that ipppd can
be both a server and client, and that different protocols can be used in the two
directions if desired.
A secrets file is parsed into words as for a options file. A secret is specified
by a line containing at least 3 words, in the order client name, server name,
secret. Any following words on the same line are taken to be a list of acceptable
IP addresses for that client. If there are only 3 words on the line, it is assumed
that any IP address is OK; to disallow all IP addresses, use "-". If the secret
starts with an ‘@’, what follows is assumed to be the name of a file from which to
read the secret. A "*" as the client or server name matches any name. When
selecting a secret, ipppd takes the best match, i.e. the match with the fewest
wildcards.
Thus a secrets file contains both secrets for use in authenticating other hosts,
plus secrets which we use for authenticating ourselves to others. Which secret to
use is chosen based on the names of the host (the ‘local name’) and its peer (the
‘remote name’). The local name is set as follows:
if the usehostname option is given,
then the local name is the hostname of this machine (with the domain appended,
if given)
else if the name option is given,
then use the argument of the first name option seen
else if the local IP address is specified with a hostname,
then use that name
else use the hostname of this machine (with the domain appended, if given)
When authenticating ourselves using PAP, there is also a ‘username’ which is the
local name by default, but can be set with the user option or the +ua option.
The remote name is set as follows:
if the remotename option is given,
then use the argument of the last remotename option seen
else if the remote IP address is specified with a hostname,
then use that host name
else the remote name is the null string "".
Secrets are selected from the PAP secrets file as follows:
* For authenticating the peer, look for a secret with client == username specified
in the PAP authenticate-request, and server == local name.
* For authenticating ourselves to the peer, look for a secret with client == our
username, server == remote name.
When authenticating the peer with PAP, a secret of "" matches any password supplied
by the peer. If the password doesn’t match the secret, the password is encrypted
using crypt() and checked against the secret again; thus secrets for authenticating
the peer can be stored in encrypted form. If the papcrypt option is given, the
first (unencrypted) comparison is omitted, for better security.
If the login option was specified, the username and password are also checked
against the system password database. Thus, the system administrator can set up
the pap-secrets file to allow PPP access only to certain users, and to restrict the
set of IP addresses that each user can use. Typically, when using the login
option, the secret in /etc/ppp/pap-secrets would be "", to avoid the need to have
the same secret in two places.
Secrets are selected from the CHAP secrets file as follows:
* For authenticating the peer, look for a secret with client == name specified in
the CHAP-Response message, and server == local name.
* For authenticating ourselves to the peer, look for a secret with client == local
name, and server == name specified in the CHAP-Challenge message.
Authentication must be satisfactorily completed before IPCP (or any other Network
Control Protocol) can be started. If authentication fails, ipppd will terminated
the link (by closing LCP). If IPCP negotiates an unacceptable IP address for the
remote host, IPCP will be closed. IP packets can only be sent or received when
IPCP is open.
In some cases it is desirable to allow some hosts which can’t authenticate them-
selves to connect and use one of a restricted set of IP addresses, even when the
local host generally requires authentication. If the peer refuses to authenticate
itself when requested, ipppd takes that as equivalent to authenticating with PAP
using the empty string for the username and password. Thus, by adding a line to
the pap-secrets file which specifies the empty string for the client and password,
it is possible to allow restricted access to hosts which refuse to authenticate
themselves.
ROUTING
When IPCP negotiation is completed successfully, ipppd will inform the kernel of
the local and remote IP addresses for the ppp interface. This is sufficient to
create a host route to the remote end of the link, which will enable the peers to
exchange IP packets. Communication with other machines generally requires further
modification to routing tables and/or ARP (Address Resolution Protocol) tables. In
some cases this will be done automatically through the actions of the routed or
gated daemons, but in most cases some further intervention is required.
Sometimes it is desirable to add a default route through the remote host, as in the
case of a machine whose only connection to the Internet is through the ppp inter-
face. The defaultroute option causes ipppd to create such a default route when
IPCP comes up, and delete it when the link is terminated.
In some cases it is desirable to use proxy ARP, for example on a server machine
connected to a LAN, in order to allow other hosts to communicate with the remote
host. The proxyarp option causes ipppd to look for a network interface on the same
subnet as the remote host (an interface supporting broadcast and ARP, which is up
and not a point-to-point or loopback interface). If found, ipppd creates a perma-
nent, published ARP entry with the IP address of the remote host and the hardware
address of the network interface found.
DIAGNOSTICS
Messages are sent to the syslog daemon using facility LOG_DAEMON. (This can be
overriden by recompiling ipppd with the macro LOG_PPP defined as the desired facil-
ity.) In order to see the error and debug messages, you will need to edit your
/etc/syslog.conf file to direct the messages to the desired output device or file.
The debug option causes the contents of all control packets sent or received to be
logged, that is, all LCP, PAP, CHAP or IPCP packets. This can be useful if the PPP
negotiation does not succeed. If debugging is enabled at compile time, the debug
option also causes other debugging messages to be logged.
Debugging can also be enabled or disabled by sending a SIGUSR1 to the ipppd pro-
cess. This signal acts as a toggle.
FILES
/var/run/ipppd.pid
Process-ID for ipppd process on ppp interface unit n.
/etc/ppp/ip-up
A program or script which is executed when the link is available for sending
and receiving IP packets (that is, IPCP has come up). It is executed with
the parameters
interface-name tty-device speed local-IP-address remote-IP-address
and with its standard input, output and error streams redirected to
/dev/null.
This program or script is executed with the same real and effective user-ID
as ipppd, that is, at least the effective user-ID and possibly the real
user-ID will be root. This is so that it can be used to manipulate routes,
run privileged daemons (e.g. sendmail), etc. Be careful that the contents
of the /etc/ppp/ip-up and /etc/ppp/ip-down scripts do not compromise your
system’s security.
/etc/ppp/ip-down
A program or script which is executed when the link is no longer available
for sending and receiving IP packets. This script can be used for undoing
the effects of the /etc/ppp/ip-up script. It is invoked with the same
parameters as the ip-up script, and the same security considerations apply,
since it is executed with the same effective and real user-IDs as ipppd.
/etc/ppp/ipx-up
A program or script which is executed when the link is available for sending
and receiving IPX packets (that is, IPXCP has come up). It is executed with
the parameters
interface-name tty-device speed network-number local-IPX-node-address
remote-IPX-node-address local-IPX-routing-protocol remote-IPX-routing-proto-
col local-IPX-router-name remote-IPX-router-name ipparam ipppd-pid
and with its standard input, output and error streams redirected to
/dev/null.
The local-IPX-routing-protocol and remote-IPX-routing-protocol field may be
one of the following:
NONE to indicate that there is no routing protocol
RIP to indicate that RIP/SAP should be used
NLSP to indicate that Novell NLSP should be used
RIP NLSP to indicate that both RIP/SAP and NLSP should be used
This program or script is executed with the same real and effective user-ID
as ipppd, that is, at least the effective user-ID and possibly the real
user-ID will be root. This is so that it can be used to manipulate routes,
run privileged daemons (e.g. ripd), etc. Be careful that the contents of
the /etc/ppp/ipx-up and /etc/ppp/ipx-down scripts do not compromise your
system’s security.
/etc/ppp/ipx-down
A program or script which is executed when the link is no longer available
for sending and receiving IPX packets. This script can be used for undoing
the effects of the /etc/ppp/ipx-up script. It is invoked with the same
parameters as the ipx-up script, and the same security considerations apply,
since it is executed with the same effective and real user-IDs as ipppd.
/etc/ppp/auth-up
This program or script is executed after successful authentication with the
following parameters: interface name, authentication user name, username of
ipppd, devicename, speed, remote number
/etc/ppp/auth-down
This program or script is executed after a disconnection with the following
parameters: interface name, authentication user name, username of ipppd,
devicename, speed, remote number
/etc/ppp/auth-fail
This program or script is executed after a authentication failure with the
following parameters: interface name, authentication user name, username of
ipppd, devicename, speed, remote number, failure reason
Valid reasons are:
1 = Timeout during pap auth
2 = pap protocol rejected
3 = pap secrets invalid
9 = Timeout during chap auth
10 = chap protocol rejected
11 = chap secrets invalid
/etc/ppp/pap-secrets
Usernames, passwords and IP addresses for PAP authentication.
/etc/ppp/chap-secrets
Names, secrets and IP addresses for CHAP authentication.
/etc/ppp/ioptions
System default options for ipppd, read before user default options or com-
mand-line options.
SEE ALSO
ttyI(4), isdnctrl(8), ipppstats(8),
RFC1144
Jacobson, V. Compressing TCP/IP headers for low-speed serial links. 1990
February.
RFC1321
Rivest, R. The MD5 Message-Digest Algorithm. 1992 April.
RFC1332
McGregor, G. PPP Internet Protocol Control Protocol (IPCP). 1992 May.
RFC1334
Lloyd, B.; Simpson, W.A. PPP authentication protocols. 1992 October.
RFC1548
Simpson, W.A. The Point-to-Point Protocol (PPP). 1993 December.
RFC1549
Simpson, W.A. PPP in HDLC Framing. 1993 December
NOTES
The following signals have the specified effect when sent to the ipppd process.
SIGINT, SIGTERM
These signals cause ipppd to terminate the link (by closing LCP), restore
the serial device settings, and exit.
SIGHUP This signal causes ipppd to terminate the link, restore the serial device
settings, and close the serial device. If the persist option has been spec-
ified, ipppd will try to reopen the serial device and start another connec-
tion. Otherwise ipppd will exit.
SIGUSR2
This signal causes ipppd to renegotiate compression. This can be useful to
re-enable compression after it has been disabled as a result of a fatal
decompression error. With the BSD Compress scheme, fatal decompression
errors generally indicate a bug in one or other implementation.
AUTHORS
Originally written by Drew Perkins, Brad Clements, Karl Fox, Greg Christy, Brad
Parker, Paul Mackerras <paulus AT cs.au> for (original) pppd.
Changes for ipppd by Klaus Franken <kfr AT suse.de> and Michael Hipp
<Michael.Hipp AT student.de>.
Removal of pppd specific options and polish by Frank Elsner <Elsner AT zrz.TU-
Berlin.DE>.
isdn4k-utils-3.7 2003/07/01 IPPPD(8)
Generated by $Id: phpMan.php,v 4.55 2007/09/05 04:42:51 chedong Exp $ Author: Che Dong
On Apache/1.3.41 (Unix) PHP/5.2.5 mod_perl/1.30 mod_gzip/1.3.26.1a
Under GNU General Public License
2009-01-09 07:09 @38.103.63.58 CrawledBy CCBot/1.0 (+http://www.commoncrawl.org/bot.html)