OSPFv3 is a routing protocol that is specifically designed for IPv6 networks but can still be used on IPv4 networks with the use of address families. To configure OSPFv3 on routers is to enable as well, the communication between different IPv6 networks. This allows for the coexistence of IPv4 and IPv6 routing information within the same OSPFv3 instance, providing a seamless transition to IPv6 in a mixed network environment.
OSPFv3 supports multiple address families by setting the instance ID value from the IPv6 reserved range to the IPv4 reserved range (64 to 95) in the router link states LSAs. By doing this, OSPFv3 is able to operate over an IPv4 network, link local addresses while still utilizing its IPv6 features. This flexibility allows for a smooth transition from IPv4 to IPv6 in networks that may be running both protocols simultaneously. OSPFv3’s ability to support point to point multiple address families makes it a versatile and adaptable routing protocol for networks of varying complexities.
It’s simple to enable IPv4 functionality to configure OSPFv3. Consider the following steps:
Step 1. Ensure that the IPv4 interface has an IPv6 address (global or link local) configured. Remember that configuring a global address also places a global address; alternatively, a link-local address can statically be configured.
Step 2. Enable the OSPFv3 process for IPv4 on the command interface with the command ospfv3 process-id ipv4 area area-id.
Configure OSPFv3 Protocol on IPv4
Router1(config)#ipv6 unicast-routing Router1(config)#ipv6 cef Router1(config)#interface loopback 0 Router1(config-if)#ip address 1.1.1.1 255.255.255.0 Router1(config-if)#ipv6 enable Router1(config-if)#ospfv3 1 ipv 4 area 0 Router1(config-if)#interface GigabitEthernet 0/0 Router1(config-if)#ip address 192.168.10.1 255.255.255.0 Router1(config-if)#duplex auto Router1(config-if)#speed auto Router1(config-if)# media-type rj45 Router1(config-if)#ipv6 enable Router1(config-if)#ospfv3 1 ipv 4 area 0 Router1(config-router)#address-family ipv4 unicast Router1(config-router)# exit-address-family
Router2(config)#ipv6 unicast-routing Router2(config)#ipv6 cef Router2(config)#interface loopback 0 Router2(config-if)#ip address 2.2.2.2 255.255.255.0 Router2(config-if)#ipv6 enable Router2(config-if)#ospfv3 1 ipv 4 area 0 Router2(config-if)#interface GigabitEthernet 0/0 Router2(config-if)#ip address 192.168.10.2 255.255.255.0 Router2(config-if)#duplex auto Router2(config-if)#speed auto Router2(config-if)# media-type rj45 Router2(config-if)#ipv6 enable Router2(config-if)#ospfv3 1 ipv 4 area 0 Router2(config-router)#address-family ipv4 unicast Router2(config-router)# exit-address-family
OSPFv3 Protocol on IPv4 Verification
Router1#show ospfv3 neighbor OSPFv3 1 address-family ipv4 (router-id 192.168.10.1) Neighbor ID Pri State Dead Time Interface ID Interface 192.168.10.2 1 FULL/DR 00:00:35 8 GigabitEthernet0/0
Router1#show ip route ospfv3 Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2 i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP a - application route + - replicated route, % - next hop override Gateway of last resort is not set 2.0.0.0/32 is subnetted, 1 subnets O 2.2.2.2 [110/1] via 192.168.10.2, 00:02:44, GigabitEthernet0/0
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