TP-LINK T3700G-28TQ User's Guide download pdf (Page 200)

188

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.

Figure 10-44 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.

Type

Code

Name Features

1 Router LSA

Originates from all the routers, and describes the router

interface which itself has already run the OSPF features and

then spreads in its advertising area.

2 Network LSA

Originates from DR, and describes the link state of all routers in

its connected network segment and then diffuses in its

advertising area.

3 Network

Summary LSA

Originates from ABR, and describes the routers of all segments

in the area and

then advertises to the backbone area, the

routers in which area will re-

summarize and then announce to

the other area.

4 ASBR

Summary LSA

Originates from ABR, and describes the routers from ABR to

ASBR and advertises the path to ASBR to the area ABR

connects.

AS External

LSA

Originates from ASBR, and describes the external route and the

accessible network obtained by other routing protocols. This

type of LSA will be flooded to the entire autonomous system.

1 2 ... 195 196 197 198 199 200 201 202 203 204 205 ... 414 415

Comments to this Manuals

No comments

TP-LINK T3700G-28TQ User's Guide Page 200

Comments to this Manuals

Related products and manuals for Software TP-LINK T3700G-28TQ