3Com Switch 8800 Advanced Software V5 Configuration Guide

Introduction to OSPF 315
Figure 96 LSAck packet format
LSA header format
All LSAs have the same header, as shown in the following figure.
Figure 97 LSA header format
Major fields:
■ LS age: The time in seconds elapsed since the LSA was originated. A LSA ages
in the LSDB (added 1 per second), but does not in transmission.
■ LS type: The type of the LSA
■ Link State ID: The contents of this field depend on the LSA’s type
■ LS sequence number: Used by other routers to judge new and old LSAs.
■ LS checksum: Checksum of the LSA except the LS age field
■ Length: The length in bytes of the LSA, including the LSA header
...
Version 5
Router ID
Area ID
Checksum AuType
Packet length
Authentication
Authentication
LSA header
0715 31
LSA header
LS age
Linke state ID
Advertising Router
Options LS type
LS sequence number
LS checksum Length
0715 31