Re-enabling OSPFv2 compatibility with RFC 1583

1. Enter the configure terminal command to access global configuration mode.
   

   device# configure terminal

2. Enter the ip router ospf command to enter OSPF router configuration mode and enable OSPFv2 on the device.
   

   device(config)# router ospf

3. Enter the rfc1583-compatibility command to re-enable OSPFv2 compatibility with RFC 1583.
   

   device(config-router-ospf-vrf-default-vrf)# rfc1583-compatibility 

The following example re-enables OSPFv2 compatibility with RFC 1583.

device# configure terminal
device(config)# router ospf 
device(config-router-ospf-vrf-default-vrf)# rfc1583-compatibility