Tuesday, June 28, 2011

Static routes after restart/reboot in Fedora/RedHat/CentOS

Static routing is the term used to refer to the manual method used to set up routing. An administrator enters routes into the router using configuration commands. This method has the advantage of being predictable, and simple to set up. It is easy to manage in small networks but does not scale well.

Question: How can I save static routes I set up in my Fedora/RedHat/CentOS Linux after I reboot server?

Answer: In Fedora Linux (or RedHat, CentOS) you can set up static routes for certain network interface (for example eth1) by editing file /etc/sysconfig/network-scripts/route-eth1.

For example, you have to save static route added by the following command:

route add -net netmask gw dev eth1

To do it, just add the following line to /etc/sysconfig/network-scripts/route-eth1:


The alternate way of doing it is to put the routes in /etc/sysconfig/static-routes. So the above route would like this like in the static-routes file:

any net netmask gw

Where any is specified above you can also set specific interfaces (such as eth1).

Here is the part /etc/init.d/interfaces code:

# Add non interface-specific static-routes.
if [ -f /etc/sysconfig/static-routes ]; then
grep "^any" /etc/sysconfig/static-routes | while read ignore args ; do
/sbin/route add -$args

Looks like any must be at the beginning of each line in /etc/sysconfig/static-routes.

/usr/share/doc/initscripts-${VERSION}/sysconfig.txt is a good place to look for these things as well

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