Show ip route table:

ip route

Edit File :

cd /etc/rc.d/

Use the following command to check the present routes.

netstat -r
netstat -rn
sudo ip route show
sudo ip route -n
sudo ip route show table local
sudo ip route show cache
sudo ip -s route show cache
sudo ip -s route get 172.20.4.0


Removing a specific route and emptying a routing table with ip route flush:

sudo ip route flush
sudo ip route flush 172.20.4.0/24

Adding routes to the startup:-

All these added routes will be lost whenever we restart the pc, in order to make these route entries permanent ot to make sure that these comes back automatically whenever a pc is restarted, issue the following commands.

Vi  /etc/rc.local

And insert the following command, save the file and exit.

route add -net 192.56.76.0 netmask 255.255.255.0 dev eth1
Route add –net 192.168.1.0/24 gw 192.168.1.1
Route add –host 192.168.1.1/32 gw 192.156.1.1

Rc.local is run every time your pc is restarted.

On Linux Gentu, you will find the routing tables under path : /etc/conf.d
edit file local.start

sudo vi /etc/conf.d/local.start