Configuring Ospfv3; Overview; Packets; Lsa Types - HPE FlexNetwork HSR6800 Configuration Manual

Configuring OSPFv3

Overview

Open Shortest Path First version 3 (OSPFv3) supports IPv6 and complies with RFC 5340 (OSPF for
IPv6).
OSPFv3 and OSPFv2 have the following similarities:
•
A 32-bits router ID and area ID
•
Packets, including Hello, DD (Data Description), LSR (Link State Request), LSU (Link State
Update), 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.

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, and has no authentication field, but is added with an Instance ID field to
support VPN per link.
Figure 96 OSPFv3 packet header
Major fields for OSPFv3 packet header 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, respectively.
•
Packet length—Packet length in bytes, including header.
•
Instance ID—Instance ID for a link.
•
0—Reserved. It must be 0.

LSA types

OSPFv3 sends routing information in LSAs, which, as defined in RFC 5340, have the following
types:
•
Router-LSA—Originated by all routers. This LSA describes the collected states of the router's
interfaces to an area, and is flooded throughout a single area only.
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