Let’s say you have this scenario: R4 and R5 are connected via a serial cable. Configure IP Addressing so that R4 and R5 are in the 192.168.45.0/24. R4 should have an IP of 192.168.45.4/24. R5 should have an IP address off 192.168.45.5/24. The catch: Do not configure an IP Address with the ip address 192.168.45.4 255.255.255.0 command directly on R4’s s1/1 interface. Let’s have a look at the different ways we can solve this….
The idea behind a backup interface is a simple one. If your main interface goes down, a secondary interface (like ISDN or frame) is brought up and traffic goes through this until connectivity is restored to the main interface. In this article we will be exploring how we can implement such a configuration using the Cisco IOS backup interface command.
In our previous tutorials on OSPF Network types (you can read Part 1 here, and Part 2 here), we looked at the OSPF broadcast, non-broadcast, point-to-multipoint, and point-to-multipoint non-broadcast network types. In this article we will be taking a look at the last of the ospf network types, namely point-to-point and loopback network types.