TP-Link JetStream T2700G-28TQ User Manual page 203

LSA Quantity: The quantity of LSA included in the LSU.
1)
LSA: A complete description of LSA.
2)
6. LSAck Packet
When receiving a LSU, the router will send to the router forwarding the LSU packet a LSAck
packet including the LSA header it receives to confirm whether the data received is correct.
7. LSA
OSPF protocol defines area and multiple router types. Via various sorts of LSA, different types of
router complete routing update caused by network changes. OSPF protocol defines 11 types of
LSA, which all have the same LSA header. As shown below, every LSA is unique in the network,
and could be identified uniquely by the key field of LSA header.
1) Age: The time passed since the LSA is generated. When the age goes over the threshold
value set by the router system, which is one hour, and the router doesn't receive an LSA
update, it will delete this LSA.
2) Type: The type of LSA. Table 10-5 enumerates several common features of LSA.
3) Link State ID: It has different meanings for different types of LSA. For details please refer to
the RFC documentation.
4) Advertising Router: ID of the router advertising this LSA.
5) Sequence Number: It indicates the uniqueness of a certain LSA, whose update would be
flooded to the network by adding 1 to the sequence number.
In the table below are the features of 6 types of common LSA.
Figure 10-43 LSU Packet
Figure 10-44 LSA Header
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