OSPF типы LSA

LSA Types

1 Router LSA - generate by router per each area. Router ID. Stay within the area.

2 Network LSA - network state. Generate by DR within the area. 

3 Summary LSA (ABR) - Generate by ABR. 

4 ASBR summary - Generate by ASBR

5 External LSA - Information about external network 

6 Multicast LSA - did not use 

7 NSSA external LSA - NSSA forbidden to use LSA 5. Generate LSA 7 for external network. 

All LSA packets except Hello carry LSA information. 

DBD

1 Router LSA describe  interface or link on the router. Or Virtual Link. 

Flags: 

V if =1 endpoint for Virtual Link

E if =1 generated by ASBR 

B if =1 generated by  ABR

Link type 

1 - p2p network

2 - Transit network (NBMA, broadcast)

3 - Stub network

4 - Virtual link

Metric - cost of link

2 Network LSA

Link State ID - DR 

Attached router - list of ID router with install AJ with DR(include DR)

3&4 Network and ASBR Summary

Link State ID - ip of advertising network 

Link State ID - ip address of ASBR

5 External-LSA

Link State ID - ip of advertising network 

E - external type. 0 - Type 1. 1 Type 2.

Forwarding address - to with IP forward packets. If 0.0.0.0 - forward to ASBR. 

External Route Tag - Tag from external route

7 NSSA external LSA

Link State ID - ip of advertising network