© Copyright Lenovo 2016 Chapter 35: Open Shortest Path First 579OSPFv3 Identifies Neighbors by Router IDWhere OSPFv2 uses a mix of IPv4 interface addresses and Router IDs to identifyneighbors, depending on their type, OSPFv3 configuration consistently uses aRouter ID to identify all neighbors.Although Router IDs are written in dotted decimal notation, and may even bebased on IPv4 addresses from an original OSPFv2 network configuration, it isimportant to realize that Router IDs are not IP addresses in OSPFv3, and can beassigned independently of IP address space. However, maintaining Router IDsconsistent with any legacy OSPFv2 IPv4 addressing allows for easierimplementation of both protocols.Other Internal ImprovementsOSPFv3 has numerous improvements that increase the protocol efficiency inaddition to supporting IPv6 addressing. These improvements change some of thebehaviors in the OSPFv3 network and may affect topology consideration, but havelittle direct impact on configuration. For example: Addressing fields have been removed from Router and Network LSAs. Flexible treatment of unknown LSA types to make integration of OSPFv3 easier. Interface network type can be specified using the command:RS G8264(config ip if)# ipv6 ospf network{broadcast|non broadcast|point to multipoint|point to point} For an interface network type that is not broadcast or NBMA, link LSAsuppression can be enabled so link LSA is not originated for the interface. Usethe command: RS G8264(config ip if)# ipv6 ospf linklsasuppressOSPFv3 LimitationsENOS 8.4 does not currently support multiple interfaces of OSPFv3 on the samelink.OSPFv3 Configuration ExampleThe following example depicts the OSPFv3 equivalent configuration of“Example 3: Summarizing Routes” on page 576 for OSPFv2.In this example, one summary route from area 1 (stub area) is injected into area 0(the backbone). The summary route consists of all IP addresses from the 36::0/32portion of the 36::0/56 network, except for the routes in the 36::0/8 range.Figure 55. Summarizing RoutesIF 310::1 IF 436::110::0/56Network 36::0/56Network36::0/32(- 36::0/8)Backbone Stub AreaSummary Route ABRArea 0(0.0.0.0) Area 1(0.0.0.1)
