Cisco Certified Network Associate (CCNA) Practice Exam

When configuring EIGRP, what command is necessary to prevent a router from participating in route advertisements?

1. no ip eigrp

2. eigrp stub

3. shutdown eigrp

4. disable eigrp route

The correct answer is: eigrp stub

When configuring Enhanced Interior Gateway Routing Protocol (EIGRP) and you want to prevent a router from participating in route advertisements while still allowing it to receive routes, the command that achieves this is to configure the router as a stub. Utilizing the EIGRP stub command means that the router will not advertise certain types of routes, effectively limiting its participation in routing while still receiving updates from neighboring routers. This can help in network scenarios where you want to reduce the complexity and traffic associated with route advertisements, particularly in branch offices or remote sites that do not need to advertise their own routes back to the core of the network. This configuration is particularly useful in a hub-and-spoke topology, where the hub router communicates with multiple spoke routers, but the spoke routers do not need to send route updates back to each other. By configuring a router as an EIGRP stub, you maintain optimal routing efficiency without unnecessary traffic or processing overhead. The other choices do not provide the same functionality or do not exist in the context of EIGRP. Understanding the purpose of the stub configuration is critical for network efficiency in scenarios where certain routers only need to receive routing updates rather than sending their own advertisements.