A Cisco router receives an IPv4 packet destined for a remote host. Place the sequential steps of the router's forwarding decision logic in the correct order from first to last.
- 1Extract the destination IPv4 address from the incoming packet header.
- 2Filter routing table entries to find candidate routes matching the destination IP based on Longest Prefix Match.
- 3Compare Administrative Distance values among candidate routes that share the exact same longest prefix length.
- 4Compare metric/cost values to select the best path if multiple routes are from the same routing protocol with equal prefix length.
- 5Determine the next-hop IP and egress interface, rewrite the Layer 2 header, and transmit the packet.
Cevap
The correct sequence begins with extracting the packet's destination IP address, applying Longest Prefix Match to identify candidate routes, comparing Administrative Distance for equal-length prefix ties, comparing metric/cost for intra-protocol ties, and completing Layer 2 encapsulation for egress transmission.
When forwarding an IP packet, a Cisco router follows a precise hierarchy: it extracts the destination address, evaluates all matching routing table entries to find the Longest Prefix Match (most specific subnet mask), breaks ties between different routing protocols using Administrative Distance (lowest wins), breaks ties within the same protocol using Metric/Cost (lowest wins), and finally resolves the Layer 2 next-hop rewrite for frame transmission.
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Router Forwarding Decision Logic Sequence