350-401 Practice Question: Examine the following EIGRP configuration…

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  EIGRP will use up to 50% of the interface bandwidth for its control traffic.

  Why this is correct

  EIGRP's `ip bandwidth-percent eigrp` command directly controls the maximum percentage of an interface's configured bandwidth that EIGRP control packets (hello, update, query, reply, and ACK) may consume. Setting it to 50 means EIGRP caps its own control-plane traffic at half the interface's bandwidth, preventing EIGRP from starving data traffic. This is a rate-limiting mechanism for routing protocol overhead, not for route selection or forwarding.

• ✗

  EIGRP will only advertise routes that have a metric within 50% of the best path.

  Why it's wrong here

  EIGRP does not filter or suppress route advertisement based on a percentage of the best-path metric; route selection is governed by the composite metric (bandwidth, delay, load, reliability), and all feasible routes are advertised to neighbors. The `ip bandwidth-percent eigrp` command operates purely at the interface level on the control-plane packet rate, so it has no bearing on which routes EIGRP advertises or how the topology table is populated. A 50% figure in the command refers to bandwidth consumption, not a metric threshold.

• ✗

  EIGRP will use 50% of the interface bandwidth for data traffic.

  Why it's wrong here

  This command is scoped to EIGRP's own control-plane traffic, not user data traffic. The interface bandwidth itself is used by data and control traffic: EIGRP packets are independent of the forwarding plane, and the bandwidth-percent setting limits only the EIGRP hello/update/etc. packets. Data traffic forwarded by the router is unconstrained by this command and instead is governed by QoS policies, interface speed, and hardware queues, so '50% for data' is a fundamental misreading of the parameter's purpose.

• ✗

  EIGRP will reduce its hello interval by 50%.

  Why it's wrong here

  The EIGRP hello interval and hold time are tuned via `ip hello-interval eigrp` and `ip hold-time eigrp` on a per-interface basis; they are unrelated to the bandwidth-percent limit. Changing the bandwidth-percent value affects only how much EIGRP traffic can be sent, not how often hello packets are transmitted. The default hello interval remains 5 seconds (or 60 on slow links) unless explicitly modified, so a 50% value would not alter that timer in any way.

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