Implementing Cisco Enterprise Advanced Routing and Services (ENARSI) — Question 161

An engineer configured Reverse Path Forwarding on an interface and noticed that the routes are dropped when a route lookup fails on that interface for a prefix that is available in the routing table.
Which interface configuration resolves the issue?

Answer options

• A. ip verify unicast source reachable-via l2-src
• B. ip verify unicast source reachable-via allow-default
• C. ip verify unicast source reachable-via any
• D. ip verify unicast source reachable-via rx

Correct answer: C

Explanation

The correct option, C, allows for the verification of unicast source addresses against any route in the routing table, thus preventing dropped packets even when a specific route lookup fails. Options A, B, and D are more restrictive and may not account for all possible routes, leading to continued packet drops.