Linux: Setting up a static route

Temporary:
Linux add a default route using route command

Route all traffic via 192.168.1.254 gateway connected via eth0 network interface:
# route add default gw 192.168.1.254 eth0
Linux add a default gateway (route) using ip command

Route all traffic via 192.168.1.254 gateway connected via eth0 network interface:
# ip route add 192.168.1.0/24 dev eth0

Persistent:
RHEL/CentOS/Fedora/Scientific Linux persistent routing configuration

Edit /etc/sysconfig/network and set default gateway IP address:
# vi /etc/sysconfig/network

Sample outputs:

## setup default gateway ##
GATEWAY=192.168.1.254

You can add additional static route for eth0 by editing /etc/sysconfig/network-scripts/route-eth0 file as follows:

192.168.12.0/24 via 192.168.1.56 dev eth0


The above config sets static routing for network 192.168.12.0/24 via 192.168.1.1 router.

The address 192.168.1.1 is the IP address leading to the remote network. It is preferably the next hop address but the address of the exit interface will work. The “next hop” means the remote end of a link, for example a gateway or router. The dev option can be used to specify the exit interface interface but it is not required. Add as many static routes as required. 



Debian / Ubuntu Linux persistence static routing configuration

Edit /etc/network/interfaces file, enter:
# vi /etc/network/interfaces

Append the following in eth0 section:

up route add -net 192.168.1.0 netmask 255.255.255.0 gw 192.168.1.254
down route del -net 192.168.1.0 netmask 255.255.255.0 gw 192.168.1.254

Save and close the file.