OSPF LSAs

Question 1

LSA Type 2

Answer 1

• Name: Network LSA
• Contains: describes the set of routers on the multi-access network, the DR, prefix and subnet
• Generated by: the DR
• Link-state ID: the IP address of the DR
• Flooded: within the area only

Question 2

LSA Type 5

Answer 2

• Name: AS External LSA
• Contains: routes being redistributed into OSPF
• Generated by: ASBR
• Link-state ID: External network number
• Flooded: All areas except NSSA

Question 3

LSA Type 7

Answer 3

• Name: NSSA External LSA
• Contains an ASBR’s redistributed routes
• Generated by: ASBR
• Flooded: within a NSSA area only. The NSSA ABR will convert this to a Type 5 LSA and flood to all other areas.

Question 4

LSA Type 1

Answer 4

• Name: Router LSA
• Contains: the status of the router’s links to the area. The link-state ID will be the originating router’s router-id.
• Generated by a router for each area to which it belongs
• Flooded: within the area only

Question 5

LSA Type 3

Answer 5

• Name: Summary LSA
• Contains: advertises to ABRs the network prefixes that originated from other areas
• Generated by: ABRs
• Flooded: all areas

Question 6

LSA Type 4

Answer 6

• Name: ASBR Summary LSA
• Contains: links to ASBRs so that all routers know where to find the ASBR. The link state ID will be the ASBR router-id.
• Generated by: ASBR
• Flooded: all areas