Routing Protocol: OSPF

I haven't made a post in week or so due to being very busy with other things, however I am going to cover the routing protocol used on the L3 Switches across the core/distribution level of the network. OSPF was chosen for the routing protocol in this network primarily on the fact it was a non-proprietary routing protocol, even with the understanding that Cisco has recently opened up use of EIGRP to non-Cisco devices. I have configuration files for the Cisco routers which allow a fully converged OSPF-routed network, which only consists of a single area with default hello and dead intervals, for simplicity. When I begin to configure the security of the network later in the year, I will change them to imitate roughly what is used in a campus environment and update this post regarding those intervals. In order to configure OSPF on L3 Switches, the following configure commands were used on each L3 Switch however only the commands on CENS1 are shown:

• Switch(config)# ip routing
• Switch(config)# router ospf 99
• Switch(config-router)# network 10.0.2.0 0.0.0.63 area 99 

Out of the box, the L3 switch does not perform any IP routing tasks. In order to enable this function, 'ip routing' must be entered in global configuration mode on the L3 switches I have used. With the 'ip routing' command entered, the switch can take advantage of RIP, OSPF and EIGRP routing protocols. As above, OSPF was the preferred routing protocol to be used in the topology. As such, the command 'router ospf 99' was entered in order to create an instance of OSPF with the process ID '99', under the global configuration mode. After the command is entered, the routing protocol sub-interface is opened to configuration on the process-id entered in the 'router ospf 99' command. In this sub-interface, networks available to the switch being configured, can be enabled to use the routing protocol process currently running. The network address and mask subnet mask have been used in order to route all information inward and outward using any network in that address space (which works out to be all networks between 10.0.2.0 through to 10.0.2.56). The selected 'area 99' was used as it differs from the standard 'area 1' used.