HP 6125G HP 6125G & 6125G/XG Blade Switches Layer 3 - IP Routing Confi - Page 216

Configuring OSPFv3 Introduction to OSPFv3 OSPFv3 overview Open Shortest Path First version 3 (OSPFv3) supports IPv6 and complies with RFC 2740 (OSPF for IPv6). The term "router" in this chapter refers to both routers and Layer 3 switches. OSPFv3 and OSPFv2 have the following similarities: • 32-bits router ID and area ID • Packets, including Hello, DD (Data Description), LSR (Link State Request), LSU (Link State Update), and LSAck (Link State Acknowledgment) • Mechanism for finding neighbors and establishing adjacencies • Mechanism for LSA flooding and aging OSPFv3 and OSPFv2 have the following differences: • OSPFv3 runs on a per-link basis, and OSPFv2 runs on a per-IP-subnet basis. • OSPFv3 supports multiple instances per link, but OSPFv2 does not. • OSPFv3 identifies neighbors by Router ID, and OSPFv2 by IP address. OSPFv3 packets OSPFv3 has the following packet types: hello, DD, LSR, LSU, and LSAck. These packets have the same packet header, which is different from the OSPFv2 packet header. The OSPFv3 packet header is only 16 bytes in length, has no authentication field, and is added with an Instance ID field to support VPN per link. Figure 77 OSPFv3 packet header Major fields for OSPFv3 packets are as follows: • Version #-Version of OSPF, which is 3 for OSPFv3. • Type-Type of OSPF packet; types 1 to 5 are hello, DD, LSR, LSU, and LSAck. • Packet length-Packet length in bytes, including header. • Instance ID-Instance ID for a link. • 0-Reserved. It must be 0. 206