IP Routing Explained

Hello Mohammad

A routing table is not executed in the same way as an ACL. When there is a destination address, it is compared to each entry in the routing table and is matched with the most accurate entry. For example:

Let’s say the destination IP is 10.96.4.7 and the routing table includes the following destinations:

172.16.1.0/24
10.96.0.0/16
192.168.7.0/24
10.96.4.0/25

The router will look at each destination. Here there would be two matches: 10.96.0.0/16 and 10.96.4.0/25. Once the router finds the first match, unlike an ACL, it will continue searching through the routing table to find a more accurate match. In this case 10.96.4.0/25 is more accurate, so this one is chosen.

Keep in mind that a routing table usually has the destinations in some sort of numerical order, so it does save time in finding the most accurate route.

I hope this has been helpful!

Laz