65
Figure 28
LSR packet format
Major fields of the LSR packets are as follows:
•
LS type
—Type of the LSA to be requested. Type 1 for example indicates the Router LSA.
•
Link state ID
—Determined by LSA type.
•
Advertising router
—ID of the router that sent the LSA.
LSU packet
LSU (Link State Update) packets are used to send the requested LSAs to the peer. Each packet carries a
collection of LSAs.
Figure 29
LSU packet format
LSAck packet
Link State Acknowledgment (LSAck) packets are used to acknowledge received LSU packets. An LSAack
packet carries the headers of LSAs to be acknowledged.
Version
3
Router ID
Area ID
Checksum
AuType
Packet length
Authentication
Authentication
LS type
Link state ID
...
Advertising router
0
7
15
31
...