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Zorluk: KolayRouting Concepts and Dynamic Routing Protocols

When a router receives a packet and evaluates multiple potential routes to a destination network, it uses specific criteria in a strict sequence to determine the best path. Order the following route selection criteria from FIRST (highest priority) to LAST (lowest priority).

  1. 1Longest Prefix Match (Most specific subnet mask)
  2. 2Lowest Administrative Distance (Protocol trustworthiness)
  3. 3Lowest Metric (Path cost calculation)

Cevap

The correct order from first to last criteria evaluated is: Longest Prefix Match, followed by Lowest Administrative Distance, and finally Lowest Metric.
Routing engines follow a strict tie-breaking sequence: Longest Prefix Match is evaluated first to find the most specific network destination. If routes have equal prefix lengths, Administrative Distance is checked next to pick the most reliable routing source. If routes stem from the same protocol with equal AD, the lowest Metric value determines the final path.

Adım Adım Çözüm

1
Evaluate subnet specificity across all available routes.
The route with the longest prefix match (e.g., /26 over /24) is selected first.
Longest prefix match always takes precedence in IP routing decisions.
2
Compare Administrative Distance if prefix lengths are equal.
The route from the protocol with the lower AD value (e.g., OSPF at 110 over RIP at 120) is chosen.
Administrative distance measures the trustworthiness of the route source.
3
Compare path metrics if routes originate from the same protocol.
The route with the lowest metric/cost (e.g., hop count or bandwidth-based cost) is preferred.
Metric acts as a tie-breaker among routes from the same routing protocol.

Anahtar Kavram

IP Routing Table Path Selection Hierarchy
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Konular

Routing Concepts and Dynamic Routing Protocols

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