What is Type-5 LSA OSPF?
The type-5 LSA is the external LSA. As the name suggests, it describes networks that are external to the OSPF domain, injected into OSPF via some form of redistribution.
How are LSA 5 and 7 represented as?
Answer: The difference between Type-5 LSA and Type-7 LSA is that Type-7 LSA can live only into NSSA area, so it will never leave the NSSA area. Instead Type-5 LSA can be propagated to the other areas (backbone and non-backbone). – Both of them are generated by the ASBR.
Why are some routes in the OSPF database but not in the routing table?
Symptom: OSPF routes and networks are not being advertised to other routers. Routers in one area are not receiving routing information for other areas. Some hosts cannot communicate with hosts in other areas, and routing table information is incomplete.
What command displays the OSPF link states types?
The show ip ospf database command displays the content of the LSDB and verifies information about specific LSAs. The output reveals the presence of different LSA types. For each LSA type, you can see which router advertised it, the age of the LSA, and the value of the link ID.
What type of router generates a Type 5 LSA?
OSPF creates a type 5 LSA for a subnet that is injected into OSPF from an external source. To inject the route, the autonomous System Border Router (ASBR), which is by definition a router that connects to a non-OSPF routing domain, uses the redistribute command.
What defines the relationship between Type 4 and Type 5 LSAs?
Type 4 – Summary ASBR LSA: Other routers need to know where to find the ASBR. This is why the ABR will generate a summary ASBR LSA which will include the router ID of the ASBR in the link-state ID field. Type 5 – External LSA: also known as autonomous system external LSA: The external LSAs are generated by the ASBR.
Which packet type is invalid for OSPF routing protocol?
OSPF
| Question | Answer |
|---|---|
| Which packet type is invalid for OSPF? Hello, LRU, LSR, LSAck, or DBD | LRU |
| In the router ospf command, does the process ID need to match on all routers? | No, unlike EIGRP, the OSPF is locally significant and does not need to match other OSPF routers. |
What type of router generates a router link LSA?
LSA Type 2 (Network LSA) packets are generated by the Designated Router (DR) to describe all routers connected to its segment directly.
What is the difference between OSPF LSA type 4 and 5?
Is there really a difference between Type 4 & 5 LSA? LSA type 4 is a summary LSA ( ASBR location) and a type 5 LSA is a external LSA which is sent from an ASBR into and ospf area depending on what type of area you setup. The link-state ID is the router ID of the described ASBR for type 4 LSAs.
Why OSPF is called Link State?
The OSPF protocol is a link-state routing protocol, which means that the routers exchange topology information with their nearest neighbors. Therefore, in a link-state routing protocol, the next hop address to which data is forwarded is determined by choosing the best end-to-end path to the eventual destination.
How do I view the external LSAs generated by router 5?
To view the external LSAs, issue the show ip ospf database external command on Router 5. The output of this command is shown below. What you can see above is that the forwarding addresses for the type 5 LSAs generated by both Router 3 and Router 4 are set to 0.0.0.0.
What are the forwarding addresses for the Type 5 LSAs generated?
What you can see above is that the forwarding addresses for the type 5 LSAs generated by both Router 3 and Router 4 are set to 0.0.0.0. In this case, the LSA to be installed in the Router 5 routing table is determined by comparing the metrics to the ASBRs generating the LSAs.
Why are my routes not showing up in the routing table?
There are several reasons for this problem, most of which deal with mis-configuration or a broken topology. When the configuration is corrected the OSPF database discrepancy goes away and the routes appear in the routing table. This document explains some of the more common reasons that can cause the discrepancy in the database.
What is the static route of router 3 and router 4?
As shown below, Router 3 and Router 4 have a static route to network 200.200.200.0 255.255.255.0, which is being redistributed into OSPF.
