Refer to the exhibit. GLBP has been configured on the network. When the interface
serial0/0/1 on router R1 goes down, how is the traffic coming from Host1 handled?
A.
The traffic coming from Host2 is forwarded through router R2 with no disruption. The
traffic from Host1 is dropped due to the disruption of the load balancing feature configured
for the glbp group.
B.
The traffic coming from both hosts is temporarily interrupted while the switchover to make
R2 active occurs.
C.
The traffic coming from Host2 is forwarded through router R2 with no disruption. Host1
sends an ARP request to resolve the MAC address for the new virtual gateway.
D.
The traffic coming from Host1 and Host2 is forwarded through router R2 with no
disruption.
Explanation:
The Gateway Load Balancing Protocol (GLBP) is a Cisco-proprietary protocol designed to
overcome the limitations of existing redundant router protocols. Some of the concepts are
the same as with HSRP/VRRP, but the terminology is different and the behavior is much
more dynamic and robust and allows for load balancing.
The trick behind this load balancing lies in the GLBP group. One router is elected the active
virtual gateway (AVG). This router has the highest priority value, or the highest IP address in
the group, if there is no highest priority. The AVG answers all ARP requests for the virtual
router address. Which MAC address it returns depends on which load-balancing algorithm it
is configured to use. In any event, the virtual MAC address supported by one of the routers
in the group is returned.
According to exhibit, Company1 is the active virtual gateway and Company2 is the standby
virtual gateway. So, when Company1 goes down, Company2 will become active virtual
gateway and all data goes through Company2.