The Problem: No OSPF routes displayed

B

The OSPF routes are a type of network route that is learned and stored in the routing table by the Open Shortest Path First (OSPF) protocol. The routing table is a database that contains information about the routes that packets can take to reach their destination.

In this scenario, the command "show route table inet.3" is issued to view the OSPF routes in the routing table, but no OSPF routes are displayed. This means that either there are no OSPF routes learned or stored in the routing table or the command used is incorrect.

Now, let's look at the answer options:

A. The OSPF routes are located in the inet4.0 routing table. This option is not correct because the inet4.0 routing table is used for IPv4 unicast routes, and OSPF routes are not limited to this routing table.

B. The OSPF routes are located in the inet.0 routing table. This option is partially correct because the inet.0 routing table is the default routing table for IPv4 unicast routes, including OSPF routes. However, there may be other routing tables where OSPF routes could also be stored, depending on the configuration.

C. The OSPF routes are located in the inet.2 routing table. This option is also partially correct because the inet.2 routing table is the default routing table for multicast routes, including OSPF multicast routes. However, this option does not consider unicast OSPF routes.

D. The OSPF routes are located in the inet4.3 routing table. This option is not correct because the inet4.3 routing table is not a default routing table and is not used for OSPF routes.

Therefore, the correct answer is B. The OSPF routes are located in the inet.0 routing table, which is the default routing table for IPv4 unicast routes, including OSPF routes. However, it is possible that OSPF routes may be stored in other routing tables, depending on the configuration.