14.5. Routing in SUSE LINUX

SUSE LINUX – Administration Guide Chapter 14. Linux in the Network / 14.5. Routing in SUSE LINUX
	14.4. Network Integration		14.6. DNS — Domain Name System

The routing table is set up in SUSE LINUX via the configuration files /etc/sysconfig/network/routes and /etc/sysconfig/network/ifroute-*. All the static routes required by the various system tasks can be entered in the /etc/sysconfig/network/routes file: routes to a host, routes to a host via a gateway, and routes to a network. For each interface that needs individual routing, define an additional configuration file: /etc/sysconfig/network/ifroute-*. Replace * with the name of the interface. The entries in the routing configuration files look like this:

DESTINATION           GATEWAY NETMASK   INTERFACE [ TYPE ] [ OPTIONS ]
DESTINATION           GATEWAY PREFIXLEN INTERFACE [ TYPE ] [ OPTIONS ]
DESTINATION/PREFIXLEN GATEWAY -         INTERFACE [ TYPE ] [ OPTIONS ]

To omit GATEWAY, NETMASK, PREFIXLEN, or INTERFACE, write - instead. The entries TYPE and OPTIONS may just be omitted.

The route's destination is in the first column. This column may contain the IP address of a network or host or, in the case of reachable name servers, the fully qualified network or host name.
The second column contains the default gateway or a gateway through which a host or a network can be accessed.
The third column contains the netmask for networks or hosts behind a gateway. The mask is 255.255.255.255, for example, for a host behind a gateway.
The last column is only relevant for networks connected to the local host such as loopback, ethernet, ISDN, PPP, and dummy device. The device name must be entered here.

The following scripts in the directory /etc/sysconfig/network/scripts/ assist with the handling of routes:

ifup-route: for setting up a route
ifdown-route: for disabling a route
ifstatus-route: for checking the status of the routes