What is routing:

Routing informs the kernel how to transfer a packet from one IP to another IP. Lets say you have the the following routers (gateways)

192.168.20.1
192.168.20.2

and the second level of private network under these gateways are as below

192.168.20.1 -> 10.10.10.0
192.168.20.2 -> 10.10.20.0

Let’s say you want to transfer a packet from IP 10.10.10.10 to 10.10.20.20 but by default the kernel will have the information of only 10.10.10.0/24.

To achive this and to transfer the packet to 10.10.20.20, we need to add a static route in the server, so that the kenel may know where to route this packet.

There are two types of routes:

1. Temporary Routes : This routes will be temporary and will not work after server reboot. Click here to set temporary routes on CentOS 7 Servers.

2. Persistant Routes : This routes will be persistant and the reboot will not affect the routes. Click here to set persistant routes on CentOS 7 Servers.