A Cisco router receives an IPv4 packet destined for a remote subnet. Place the operational steps performed by the router to evaluate IPv4 static routes and forward the packet into the correct sequential order from first to last.
- 1Extract and inspect the destination IPv4 address from the incoming packet header.
- 2Search the routing table for matching static routes and identify the candidate entry with the longest prefix match.
- 3Evaluate Administrative Distance if multiple static routes exist for the identical network prefix.
- 4Encapsulate the packet into a Layer 2 frame and transmit it out the resolved exit interface toward the next hop.
Answer
The correct sequence of operations is: (1) Extract and inspect the destination IPv4 address from the incoming packet header, (2) Search the routing table for matching static routes and identify the candidate entry with the longest prefix match, (3) Evaluate Administrative Distance if multiple static routes exist for the identical network prefix, and (4) Encapsulate the packet into a Layer 2 frame and transmit it out the resolved exit interface toward the next hop.
When an IPv4 packet arrives on a Cisco router interface, the router inspects the destination IP address in the packet header. It then searches the routing table to find all matching network prefixes, selecting the entry with the longest prefix match (most specific mask). If there are multiple static routes configured for the exact same prefix length, the router breaks the tie by choosing the route with the lowest Administrative Distance. Finally, the router determines the exit interface/next-hop IP, rewrites the Layer 2 frame, and transmits the packet.
Step-by-Step Solution
Key Concept
IPv4 Static Route Lookup and Forwarding Decision Logic