OSPFv3 Routing Protocol参考.ppt

Implementing IPv6 OSPFv3 Routing Protocols IPv6 Routing Protocols IPv6 routing types Static RIPng (RFC 2080) OSPFv3 (RFC 2740) IS-IS for IPv6 MP-BGP4 (RFC 2545/2858) EIGRP for IPv6 The ipv6 unicast-routing command is required to enable IPv6 before any routing protocol configured. OSPF Version 3 (OSPFv3) (RFC 2740) Similar to IPv4 Same mechanisms, but a major rewrite of the internals of the protocol Updated features for IPv6 Every IPv4-specific semantic removed Carry IPv6 addresses Link-local addresses used as source IPv6 transport OSPF for IPv6 currently an IETF proposed standard OSPFv3—Hierarchical Structure Topology of an area is invisible from outside of the area: LSA flooding is bounded by area. SPF calculation is performed separately for each area. Backbones must be contiguous. All areas must have a connection to the backbone: Otherwise a virtuallink must be used to connect to the backbone. OSPFv3—Similarities with OSPFv2 OSPFv3 is OSPF for IPv6 (RFC 2740) Based on OSPFv2, with enhancements Distributes IPv6 prefixes Runs directly over IPv6 OSPFv3 and OSPFv2 can be run concurrently, because each address family has a separate SPF (ships in the night). OSPFv3 uses the same basic packet types as OSPFv2: Hello Database description (DBD) Link state request (LSR) Link state update (LSU) Link state acknowledgment (ACK) OSPFv3—Similarities with OSPFv2 Neighbor discovery and adjacency formation mechanism are identical. RFC-compliant NBMA and point-to-multipoint topology modes are supported. Also supports other modes from Cisco, such as point-to-point and broadcast, including the interface. LSA flooding and aging mechanisms are identical. Enhanced Routing Protocol SupportDifferences from OSPFv2 OSPF packet type OSPFv3 has the same five packet types, but some fields have been changed. All OSPFv3 packets have a 16-byte header vs. the 24-byte header in OSPFv2. OSPFv3 Differences from OSPFv2 OSPFv3 protocol processing is per link, not per subnet IPv6 connects