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Figure 30
LSAck packet format
...
LSA header format
All LSAs have the same header.
Figure 31
LSA header format
Major fields of the LSA header are as follows:
•
LS age: Time, in seconds, elapsed since the LSA was originated. An LSA ages in the LSDB (added
by 1 per second), but does not age during transmission.
•
LS type: 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: Length in bytes of the LSA, including the LSA header.
Formats of LSAs
1.
Router LSA