Cisco Certified Network Associate (CCNA) Practice Exam

In GLBP, which router responds to client ARP requests?

1. The active virtual gateway

2. The standby router

3. Any router in the group

4. The highest priority router

The correct answer is: The active virtual gateway

In Gateway Load Balancing Protocol (GLBP), the active virtual gateway is responsible for responding to client ARP requests. This is because the active virtual gateway serves as the primary point of entry for devices that need to communicate with the virtual IP address managed by the GLBP group. When a client sends out an Address Resolution Protocol (ARP) request for the virtual IP address, the active virtual gateway replies with its own MAC address, enabling the client to route its packets to one of the routers in the GLBP group. This functionality is crucial for load balancing purposes, as it allows multiple routers to share the traffic directed towards a single virtual IP address. The active virtual gateway ensures that client requests are distributed among the available routers effectively, facilitating optimal resource utilization and redundancy. While the standby router and the highest priority router play important roles in maintaining the GLBP operation and ensuring failover capabilities, it is specifically the active virtual gateway that handles the ARP requests from clients. Any router in the group does participate in the load balancing process, but it does not respond to ARP requests directed at the virtual IP unless it assumes the role of the active virtual gateway.