Examkin

Question

Difficulty: MediumRouting Concepts and Dynamic Routing Protocols

A network administrator is evaluating routing paths on a branch router. The router receives two updates via Routing Information Protocol (RIPv2) for destination network 192.168.50.0/24192.168.50.0/24. Path 1 traverses four intermediate routers across a high-speed 10 Gbps10\text{ Gbps} optical link. Path 2 traverses two intermediate routers across a legacy 1.544 Mbps1.544\text{ Mbps} T1 connection. Which path will the router select for insertion into its Routing Information Base (RIB), and why?

  1. Path 2, because RIP uses hop count as its sole metric and selects the path with fewer router hops regardless of link bandwidth.Answer
  2. B
    Path 1, because Layer 3 dynamic routing protocols automatically convert physical interface speed into link-state cost metrics.
  3. C
    Path 1, because high-speed optical interfaces lower the administrative distance of the dynamic route.
  4. D
    Both Path 1 and Path 2 will be installed equally for load balancing because RIP ignores metric differences across WAN links.

Answer

Path 2 will be selected because RIP uses hop count as its metric, prioritizing the path with 2 hops over the path with 4 hops regardless of underlying interface bandwidth.
Routing Information Protocol (RIP) is a distance-vector protocol that measures route desirability solely by hop count (up to a maximum of 15 hops). Even though Path 1 offers significantly higher bandwidth, RIP cannot evaluate link speed and will choose Path 2 due to its lower hop count of 2 versus 4.

Step-by-Step Solution

1
Identify the routing protocol and its metric type
The scenario specifies RIPv2, which is a distance-vector routing protocol that uses hop count as its single routing metric.
Different dynamic routing protocols evaluate path desirability using distinct metric criteria (e.g., hop count for RIP, bandwidth/cost for OSPF).
2
Compare the metric values for both candidate paths
Path 1 has a metric of 4 hops, while Path 2 has a metric of 2 hops.
Lower metric values indicate a more desirable route within the same routing protocol.
3
Determine RIB selection based on routing logic
The router selects Path 2 with a hop metric of 2, ignoring the interface bandwidth differences (10 Gbps10\text{ Gbps} vs 1.544 Mbps1.544\text{ Mbps}).
RIP does not evaluate link speed or latency when making path selection decisions.

Key Concept

Distance-vector routing protocols like RIP base path selection strictly on hop count, ignoring interface bandwidth or speed.
Rate this question

Topics

Routing Concepts and Dynamic Routing Protocols

More questions from this topic