IGRP Path Selection — Default Composite Metric Inputs Which default metric components does IGRP consider when computing the best path to a remote network? (Items: 1) Hop count, 2) MTU, 3) Cumulative interface delay, 4) STP, 5) Path bandwidth value)

Introduction / Context:IGRP (the precursor to EIGRP) uses a composite metric that reflects link performance. Knowing which parameters are included by default clarifies why a “shortest-hop” path may lose to a path with higher bandwidth and lower delay.

Given Data / Assumptions:

• IGRP’s composite metric can factor bandwidth, delay, reliability, and load.
• By default, reliability and load are not active factors.
• Hop count, MTU, and STP are not default IGRP metric inputs.

Concept / Approach:By default, IGRP considers path bandwidth (typically the minimum bandwidth along the path) and cumulative delay (sum of interface delays). These values produce a metric that prefers faster, lower-latency paths even if they traverse more hops. Hop count is a sanity limit but not a metric input. MTU and STP (spanning tree) are irrelevant to IGRP metric calculations.

Step-by-Step Solution:List candidate components.Mark bandwidth (5) and delay (3) as default active.Exclude hop count, MTU, and STP as non-metric inputs by default.Select “3 and 5.”

Verification / Alternative check:Documentation shows IGRP metric formula incorporating K1bandwidth + K3delay by default (with other K values at zero), confirming bandwidth and delay are the defaults.

Why Other Options Are Wrong:

• A/C/D/E: Include parameters that are not default inputs for IGRP metric calculation.

Common Pitfalls:Confusing EIGRP’s extended metric knobs with IGRP’s defaults; although related, defaults still center on bandwidth and delay.

Final Answer:3 and 5