OSPF Evaluation Sim
You have been asked to evaluate an OSPF network and to answer questions a customer has about its
operation. Note: You are not allowed to use the show running-config command.
Although in this sim we are not allowed to use “show running-config” command but we post the configuration
here so that you can understand more about the topology.
Some notices from above configuration:
- The OSPF network type between R2 & R3 is non broadcast.
- R3 and R4 is running virtual-link to connect Area 2 & 3 to Area 0
- Area 2 is a NSSA area while Area 3 is a Totally Stubby area
To check OSPF LSA we should use the “show ip ospf database” command on R5:
In this sim there is no LSA Type 4 because there is no ASBR so maybe this question wants to ask about LSA
Type 3 (Summary Net Link States).
Note: LSA Type 4 is generated by ABR, not ASBR but without ASBR inside the network there are no LSA Type 4 generated. For more information about OSPF LSA Types please read our OSPF LSA Types Lab tutorial.
R3 advertises LSA Type 1 to R4 then R4 converts it into Type 3 and sends to R5 (because R4 is the ABR) so we see the “Link ID” 126.96.36.199 of R3 is advertising by R4 (188.8.131.52). According to the “Age” column, this LSA was advertised 1858 seconds ago.