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, R1 is the active virtual gateway and R2 is the standby virtual gateway. So, when R1 goes down, R2 will become active virtual gateway and all data goes through R2.
I think the correct answer A. Because the track decrement 10 a priority of 110 and the lower threshold of 95. 110 – 10 = 100 means the role of the AGB will remain R1
I was wrong the correct answer D. R1 will be the AVF
I don’t understand why the traffic from Hosts 1 and 2 is necessarily forwarded through R2? It can be R1 as well. With the weight 110-10=100 it remains an AVF.
The set of answers would have fit better if it had followed that R1 quit AVF group after Serial0/0/1 went down.
@VNN, you are right, R1 is still an AVF even if S0/0/1 goes down.
As currently depicted, R2 is the AVG since it has the highest IP address and no priority configured. The default load balancing is round robin, so every other new arp request for 10.21.8.10 will be sent to R1, which will fail to forward the traffic.