Configuring OSPF

Cisco OSPF Implementation

The Cisco implementation conforms to the OSPF Version 2 specifications detailed in the Internet RFC 2328. The following list outlines key features supported in the Cisco OSPF implementation:

  • Stub areas

  • Route redistribution

  • Authentication

  • Routing interface parameters

  • Virtual links

  • Not-so-stubby area (NSSA

  • OSPF over demand circuit

For more information on each key OSPF features, see https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_ospf/configuration/xe-3s/iro-xe-3s-book/iro-cfg.html#GUID-A999A739-6B1D-4E5E-9396-F7531469D805.

Limitation for OSPF

  • OSPFv3 is not supported.

How to Configure OSPF

Enabling OSPF

Before configuring, you need to enable OSPF.

To enable OSPF at the global configuration mode, enter the following commands:


enable
configure terminal
router ospf process-id
router-id <loopback ip-address>
network ip-address wildcard-mask area area-id
end

Configuring OSPF on BDI

Before configuring, you need to enable OSPF.

To enable OSPF on the BDI interface, enter the following commands:


enable
configure terminal
interface BDI <bdi-no>
ip address <ip-address > <subnet-mask>
ip ospf <process-id> area <area-id>
end

For more information, see How to Configure OSPF.

Configuring Loopback on OSPF Interface

To configure loopback on OSPF interface, enter the following commands: 


interface loopback<loopback-no> 
ip address <ip-address > <subnet-mask>
ip ospf <process-id> area <area-id>

Configuration Examples for OSPF

Refer the following examples on various configurations for OSPF.