Ferris Plastics, Inc. is a medium sized company, with an enterprise network (access, distribution and core switches) that provides LAN connectivity from user PCs to corporate servers. The distribution switches are configured to use HSRP to provide a high availability solution.
* DSW1 -primary device for VLAN 101 VLAN 102 and VLAN 105
* DSW2 - primary device for VLAN 103 and VLAN 104
* A failure of GigabitEthemet1/0/1 on primary device should cause the primary device to release its status as the primary device, unless GigabitEthernet1/0/1 on backup device has also failed.
Troubleshooting has identified several issues. Currently all interfaces are up. Using the running configurations and show commands, you have been asked to investigate and respond to the following question.



All interfaces are active. DSW2 has not become the active device for the VLAN 103 HSRP group. As related to the VLAN 103 HSRP group, what can be done to make the group function properly?
Correct Answer: C
Explanation: The reason DSW2 has not become the active switch for Vlan103 is because the priority value of DSW1 is higher than that of DSW2. In order to make DSW2 become the active switch, we need to increase DSW2's priority (to higher than 200) or decrease DSW1's priority (to lower than 190) -> B and C are correct.
But there is another requirement from this question that "A failure on gig1/0/1 on primary device should cause the primary device to release its status as the primary device, unless GigabitEthernet 1/0/1 on backup device has also failed". This requirement makes answer B incorrect. For example, we choose to decrease the priority value on DSW1 to 160 (according to answer B) then DSW2 will become active switch (that is good). When Gi1/0/1 on DSW2 goes down, the priority of DSW2 will be 190 - 50 = 140 < 160 -> DSW1 will become new active switch (it is good, too). But when Gi1/0/1 on DSW1 also goes down, the priority of DSW1 will be 160 - 10 = 150 and it is still greater than 140 of DSW2 -> DSW2 cannot retake the active role as the requirement of this question.