Controlling RIP advertisements: Which command suppresses RIP updates from being sent out a specific interface while still allowing that interface to receive RIP updates (i.e., passive on that interface)?

Introduction / Context:
On edge or user-facing interfaces, you generally do not want a routing protocol to form neighbor relationships or spew periodic updates, yet you may still want to learn routes or at least advertise the connected network via other active interfaces. The passive-interface feature provides exactly this control.

Given Data / Assumptions:

• The routing protocol is RIP (distance-vector, periodic updates).
• We want to stop outbound RIP updates on a chosen interface.
• We still allow reception of updates (where applicable) and keep the network in the process.

Concept / Approach:

The correct context is the routing process configuration mode. From router rip, issue passive-interface (e.g., s0). This prevents outbound updates on that interface while maintaining the interface in the RIP process. On broadcast-based RIP, the router will not send updates out but can still process received ones.

Step-by-Step Solution:

Verification / Alternative check:

Packet captures on interface s0 should show no outbound RIP updates while other RIP neighbors remain unaffected. show ip rip database confirms learned routes still exist via other interfaces.

Why Other Options Are Wrong:

Option A is not a valid method to control RIP; it disables routing on an interface broadly (and is not standard syntax).

Option B uses interface configuration mode; passive needs to be under the protocol process, not per-interface config mode.

Option D is not valid IOS syntax.

Common Pitfalls:

Confusing passive-interface behavior across protocols (e.g., OSPF passive prevents forming adjacencies entirely); forgetting to verify passive settings after template deployments.

Final Answer:

Router(config-router)# passive-interface s0