Multiarea OSPF - Configure
#router ospf 10 #router-id 1.1.1.1 #network 10.1.1.1 0.0.0.0 area 1 #network 10.1.2.1 0.0.0.0 area 1 #network 192.168.10.1 0.0.0.0 area 0
Multiarea OSPFv3 - Configure
#ipv6 router ospf 10 #router-id 1.1.1.1
#int g0/0 #ipv6 ospf 10 area 1
Interarea route summarization
Interarea route summarization occurs on ABRs and applies to routes from within each area.
External route summarization
External route summarization is specific to external routes that are injected into OSPF via route redistribution.
Summarizing Area 1 Routes
#router ospf 10 #area 1 range 10.1.0.0 255.255.252.0