Users Guide

chosen to redistribute the inactive OSPF routes, OSPF removes the route learned from the peer and retains only the leaked
route.
To redistribute active and inactive IPv4/IPv6 routes from other unicast protocols into OSPF:
1. Configure a route-map to match the inactive-path-additive rule.
route-map route-map-name
match inactive-path-additive
2. Apply the route-map to the redistribute command.
redistribute {connected [route-map map-name] | imported-ospf-routes [route-map map-
name] | bgp AS-number [route-map map-name] | static [route-map map-name]}
View OSPF configuration - redistribute active routes
OS10(conf-router-ospf-10)# do show running-configuration ospf
!
router ospf 10
redistribute bgp 4 route-map aloha
redistribute connected route-map aloha
redistribute static route-map aloha
!
Redistribute active and inactive IPv4 BGP routes into OSPF
OS10# configure terminal
OS10(config)# route-map redis-inactive-routes
OS10(config-route-map)# match inactive-path-additive
OS10(config-route-map)# exit
OS10(config)# router ospf 10
OS10(config-router-ospf-10)# redistribute bgp 100 route-map redis-inactive-routes
Redistribute active and inactive IPv6 static routes into OSPF
OS10# configure terminal
OS10(config)# route-map redis-inactive-routes
OS10(config-route-map)# match inactive-path-additive
OS10(config-route-map)# exit
OS10(config)# router ospfv3 20
OS10(config-router-ospfv3-20)# redistribute static route-map redis-inactive-routes
OSPFv2
OSPFv2 supports IPv4 address families. OSPFv2 routers initially exchange hello messages to set up adjacencies with neighbor
routers. The hello process establishes adjacencies between routers of the AS. It is not required that every router within the
AS areas establish adjacencies. If two routers on the same subnet agree to become neighbors through this process, they begin
to exchange network topology information in the form of LSAs.
In OSPFv2, neighbors on broadcast and non-broadcast multiple access (NBMA) network links are identified by their interface
addresses, while neighbors on other types of links are identified by router-identifiers (RID).
Enable OSPFv2
OSPFv2 is disabled by default. Configure at least one interface as either Physical or Loopback and assign an IP address to the
interface. You can assign any area besides area 0 a number ID. The OSPFv2 process starts automatically when you configure it
globally and you can enable it for one or more interfaces.
1. Enable OSPF globally and configure an OSPF instance in CONFIGURATION mode.
router ospf instance-number
930
Layer 3