routes(5)

NAME

routes - configure the routing table

SYNOPSIS

/etc/sysconfig/network/routes
/etc/sysconfig/network/ifroute-*

DESCRIPTION

The files /etc/sysconfig/network/routes and /etc/syscon fig/network/ifroute-config are parsed by the script /etc/sysconfig/network/scripts/ifup-route which sets up routing for an interface/configuration. ifup-route is used by /sbin/ifup, which is the command line user inter face for setting up network interfaces.

/etc/sysconfig/network/routes is used for every interface while /etc/sysconfig/network/ifroute-config is used only for the network interface configuration stored in
/etc/sysconfig/network/ifcfg-config, that means only for a certain interface. (See a discussion of the notions con_
figuration, interface and device in ifup(8).)

At boot time /etc/init.d/network calls ifup for every existing configuration and uses ifup-route directly to set up special routes which do not belong to a certain inter
face.

The current routes can be seen by issuing:: /sbin/ip route list
which will give the current routing table.

Syntax

The files /etc/sysconfig/network/routes and /etc/syscon fig/network/ifroute-config use the same syntax. The only difference is the interpretation of an empty interface
field. See 4th column below.

Lines beginning with # and blank lines are ignored. There are 5 columns with special meaning. Write a dash "-" if
you want to omit an entry for a field. If all following
fields in the line are empty too, you can even omit the
dash.

The first column gives the destination, written as the IPaddress of a host or a network. The heading default indi cates that the route is the default gateway. Do
not use 0.0.0.0 for this purpose. A prefixlen can be used;
e.g., 10.10.0.0/16 is valid.

The second column contains the gateway. Write here the regular IP-address of a host which routes the packages to
a remote host or remote network. You can omit this infor
mation for rejecting routes.

The third column gives the netmask for a remote host or remote network behind a gateway. For the default route or
if you were using a prefixlen in the first column, you can
omit it.

The fourth column gives the name of the interface of the local networks (lo, eth0, eth0:1, eth1, isdn0, ppp0,
dummy0, ...).

If you leave this field empty the result depends on the
file you are using. In /etc/sysconfig/network/routes the field is interpreted as no interface information avail
able. That is sufficient for the most routes you may set
up, but if you have multiple interfaces this route is set
up with every single interface you activate. This may lead
to error messages in the syslog. If you see such an error
message which tells you "... this needs NOT to be AN
ERROR" then check if you wrote the wrong ip addresses or
if it occurs because it's being set up with the wrong
interface.

In the latter case you may want to use /etc/sysconfig/net work/ifroute-config instead. Here an empty interface field is always replaced with the interface name that is cur
rently being activated. This makes sense because this file
is only used for one configuration (for one interface).
This is even necessary if you use several hotpluggable
devices, because you cannot know the name of the interface
that is used with a configuration for a certain device
before.

The fifth column can be used to specify the type of a route:

unicast: The route entry describes real paths to the desti
nations covered by the route prefix.
local The destinations are assigned to this host. The: packets are looped back and delivered locally.
broadcast: The destinations are broadcast addresses. The pack
ets are sent as link broadcasts.
multicast: A special type used for multicast routing. It is
not present in normal routing tables.
throw A special control route used together with policy: rules. If such a route is selected, lookup in this
table is terminated pretending that no route was
found. Without policy routing it is equivalent to
the absence of the route in the routing table. The
packets are dropped and the ICMP message net
unreachable is generated. The local senders get an ENETUNREACH error.
unreachable: These destinations are unreachable. Packets are
discarded silently. The local senders get an EINVAL
error.
prohibit: These destinations are unreachable. Packets are
discarded and the ICMP message communication admin_ istratively prohibited is generated. The local senders get an EACCES error.
blackhole: These destinations are unreachable. Packets are
discarded silently. The local senders get an EINVAL
error.
nat A special NAT route. Destinations covered by the: prefix are considered to be dummy (or external)
addresses which require translation to real (or
internal) ones before forwarding. The addresses to
translate to are selected with attribute 'via'.
Any remaining columns, if given, are appended to the route command. This makes it possible to pass special options for this route. Columns which are not needed should con tain a minus sign ( - ) to ensure that the parser cor rectly interprets the command.

EXAMPLES

An example with common network interfaces and some static
routes:

# Destination Dummy/Gateway Netmask De
vice # 127.0.0.0 0.0.0.0 255.255.255.0 lo 204.127.235.0 0.0.0.0 255.255.255.0
eth0 default 204.127.235.41 0.0.0.0
eth0 207.68.156.51 207.68.145.45 255.255.255.255
eth1 192.168.0.0 207.68.156.51 255.255.0.0
eth1
An example for routing entries for synchronous ppp over a
ISDN connection.
# Destination Dummy/Gateway Netmask De
vice # 127.0.0.0 0.0.0.0 255.255.255.0 lo 193.102.150.13 0.0.0.0 255.255.255.255
ippp0 default 193.102.150.13 0.0.0.0
ippp0

NOTES

SuSE Linux >= 8.0 uses the ip command from the iproute2 package to setup the network and routes. Please see the
documentation distributed with this package for more
information.

FILES

/etc/sysconfig/network/routes /etc/sysconfig/network/ifroute-config

AUTHOR

Michal Svec <msvec@suse.cz>
Christian Zoz <zoz@suse.de>
Mads Martin Joergensen <mmj@suse.de>

Thanks to Werner Fink <werner@suse.de> for the old
route.conf(5). Parts of the ip reference by Alexey
Kuznetsov <kuznet@ms2.inr.ac.ru> were also used.

docs.sk

comprehensive documentation repository

See also