Refer to the topology below. R1 and R2 are configured to run HSRP. The network administrator wants to ask you about how HSRP operates in the vent of a device failure.
Check the HSRP state of R1 via the “show stanby” command:
R1 is the active router for HSRP group 1 (subnet 172.16.10.0/24) so all traffic will be sent to it.
When Ethernet0/0 goes down the priority is decreased by 40 (standby 1 track 1 decrement 40). Therefore when it recovers the priority is increased by the same value of 40.
HSRP Group 2 is connected via the E1/0 interfaces on both routers so we should check them carefully via the “show running-config” command:
As we can see there is no authentication on R1 while R2 requires authentication with password “cisco123” -> Authentication between R1 & R2 fails so R1 & R2 cannot exchange HSRP messages -> both R1 & R2 will claim the active role for HSRP group 2. You can verify again with the “show standby” command.
Use the “show standby” command on R1 to get the virtual MAC addres of HSRP group 1: