Difficulty: Easy
Correct Answer: The update will be ignored and no further action will occur.
Explanation:
Introduction / Context:
RIP chooses routes based on minimum hop count. When multiple advertisements for the same prefix arrive, RIP keeps the lowest-hop path. Understanding how RIP treats worse paths helps explain stable behavior and reduces unnecessary churn.
Given Data / Assumptions:
Concept / Approach:
RIP installs the best path by hop count. If a newly received advertisement has a worse metric, the router ignores it for route selection. Only if the existing route becomes invalid (for example, times out) or a strictly better metric is learned will the RIB change. Triggered updates and holddown rules further stabilize choices by damping flaps.
Step-by-Step Solution:
Compare metrics: existing hop count vs. new hop count.If new hop count > existing hop count → mark as worse.RIP ignores worse paths; no RIB replacement occurs.Maintain current entry until a better or valid replacement appears.
Verification / Alternative check:
Observe with debug ip rip; you will see advertisements received but not installed if their metric is inferior to the current entry.
Why Other Options Are Wrong:
Common Pitfalls:
Confusing “higher metric” with “fresher information”; freshness does not override worse metric in RIP.
Final Answer:
The update will be ignored and no further action will occur.
Discussion & Comments