Adding Static Routes In CentOS

There are a number of ways of adding static routes in Linux (CentOS). The easiest way of course is from the terminal by using one of the following examples:

How to add a static route for a specific host in Linux.
route add -host 192.168.1.47 gw 192.168.10.1
route del -host 192.168.1.47 gw 192.168.10.1


How to add a static route for a specific network in Linux.
route add -net 192.168.1.0/24 gw 192.168.10.1
route del -net 192.168.1.0/24 gw 192.168.10.1

How to add a default gateway.
route add default gw 192.168.10.1
route del default gw 192.168.10.1

The best place to add the default gateway is in the file /etc/sysconfig/network which would then look something like the below.

NETWORKING=yes
NETWORKING_IPV6=yes
HOSTNAME=server.example.com
GATEWAY=192.168.0.10

Also note that default gateways are added on a per interface level in their startup files located in /etc/sysconfig/network-scripts. Example: /etc/sysconfig/network-scripts/ifcfg-eth0

One of the places to add a static route so it is added each time you reboot the server is to add it to /etc/rc.d/rc.local. Your rc.local file would then look something like the below.

#!/bin/sh
#
# This script will be executed *after* all the other init scripts.
# You can put your own initialization stuff in here if you don't
# want to do the full Sys V style init stuff.

touch /var/lock/subsys/local

# Static Routes
/sbin/route add -net 192.168.1.0/24 gw 192.168.10.1
/sbin/route add -host 192.168.1.47 gw 192.168.10.1