ipppd - (ISDN) Point to Point Protocol daemon
/usr/sbin/ipppd [ options ] [ device ]
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 encapsulating datagrams over serial links, an
extensible Link Control Protocol (LCP), and a family of Network Control
Protocols (NCP) for establishing and configuring different 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).
This special (ISDN) PPP daemon is a modified version of pppd and
provides synchronous PPP for ISDN connections.
If you need asynchronous PPP over ISDN lines use pppd instead with
the ISDN character devices, see ttyI(4).
The ipppd can handle multiple devices. This is necessary to
link several connections 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 netdevice layer by
'isdnctrl hangup <device>'.
The facility to configure the daemon via file
/etc/ppp/ioptions.<devname> is disabled. The 'file' option or the
command line may be used for individual configuration.
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 daemon!
- <device>
- Communicate over the named device. The string "/dev/" is
prepended if necessary. If no device name is given, or if the name of the
controlling terminal 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
omitted. 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 information 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 specified, 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 callback 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 negotiation, 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
purposes. 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 confuse 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 number, 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 hexadecimal 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-serperated 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
permit 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 networking code send data packets of no more than
n bytes through the PPP network 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 negotiated 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 filter
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
connection until a valid LCP packet is received from the peer (as for the
`passive' 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
password 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
authentication 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
'pointopoint' 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 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.
ipppd provides system administrators with sufficient access
control that PPP access to a server machine can be provided to legitimate
users without fear of compromising 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 individual
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 authenticate 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 themselves 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.
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 interface. 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
permanent, published ARP entry with the IP address of the remote host and
the hardware address of the network interface found.
Messages are sent to the syslog daemon using facility LOG_DAEMON.
(This can be overridden by recompiling ipppd with the macro LOG_PPP
defined as the desired facility.) 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 process. This signal acts as a toggle.
- /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-protocol
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 command-line options.
- 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
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 specified, ipppd will try to reopen the serial device and
start another connection. 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.
Originally written by Drew Perkins, Brad Clements, Karl Fox, Greg
Christy, Brad Parker, Paul Mackerras <paulus@cs.anu.edu.au> for
(original) pppd.
Changes for ipppd by Klaus Franken <kfr@suse.de> and Michael
Hipp <Michael.Hipp@student.uni-tuebingen.de>.
Removal of pppd specific options and polish by Frank Elsner
<Elsner@zrz.TU-Berlin.DE>.