66
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.
LSAs formats
•
Router LSA
..
.
