Routing Table

A

The routing table is a critical component in a router, as it contains information on how to forward packets to their destinations. Here are detailed explanations for each answer option:

A. The routing table exists in the control plane only. This statement is incorrect. While the routing table is maintained in the control plane, it is also installed in the forwarding plane. This is because the forwarding plane is responsible for actually forwarding packets based on the information in the routing table.

B. The routing table exists in the control plane and in the forwarding plane. This statement is correct. As mentioned above, the routing table is maintained in the control plane and installed in the forwarding plane. This allows the forwarding plane to quickly look up the appropriate next-hop for each packet it receives.

C. The routing table contains both active and inactive routes. This statement is also correct. The routing table can contain both active and inactive routes. Active routes are those that are currently being used to forward traffic, while inactive routes are those that are not currently being used but are still stored in the routing table. Inactive routes may be kept in the routing table in case a more preferred route becomes unavailable.

D. The routing table is stored on compact flash. This statement is incorrect. The routing table is typically stored in RAM, not on compact flash. This allows for fast lookups and updates to the routing table, which is essential for efficient packet forwarding. However, some routers may have the option to save the routing table to non-volatile storage such as a hard disk or flash memory.