An enterprise router receives dynamic routing updates from multiple protocols for the exact same destination network prefix. Place the processing steps in the correct order that the router follows to evaluate these updates and install the optimal path into the Forwarding Information Base (FIB).
- 1Receive routing updates containing the destination IP prefix and subnet mask from dynamic routing processes.
- 2Evaluate Administrative Distance (AD) to prioritize the route from the most trustworthy routing protocol source.
- 3Compare protocol-specific metrics if multiple routes exist from the same routing protocol.
- 4Install the winning route entry into the Forwarding Information Base (FIB) for hardware packet forwarding.
Answer
The correct sequence begins with receiving the routing updates, followed by evaluating Administrative Distance across different protocols, comparing metrics within the winning protocol, and finally installing the selected route into the Forwarding Information Base.
When a router learns multiple routes to the exact same prefix, it first receives all update advertisements. It then uses Administrative Distance (AD) to evaluate protocol trustworthiness. If the preferred protocol advertises multiple candidate paths, the router uses the protocol metric to break the tie. Finally, the chosen route is moved into the Forwarding Information Base (FIB) for rapid data plane forwarding.
Step-by-Step Solution
Key Concept
Route Selection Hierarchy (Administrative Distance vs Metric and FIB Programming)