In GLBP, which router will respond to client ARP requests?
A. The active virtual gateway will reply with one of four possible virtual MAC addresses. B. All GLBP member routers will reply in round-robin fashion. C. The active virtual gateway will reply with its own hardware MAC address. D. The GLBP member routers will reply with one of four possible burned in hardware addresses.
Correct Answer: A
Explanation:
One disadvantage of HSRP and VRRP is that only one router is in use, other routers must wait for the primary to fail because they can be used. However, Gateway Load Balancing Protocol (GLBP) can use of up to four routers simultaneously. In GLBP, there is still only one virtual IP address but each router has a different virtual MAC address.
First a GLBP group must elect an Active Virtual Gateway (AVG). The AVG is responsible for replying ARP requests from hosts/clients. It replies with different virtual MAC addresses that correspond to different routers (known as Active Virtual Forwarders – AVFs) so that clients can send traffic to different routers in that GLBP group (load sharing).