Hello
Both switches should have same IOS while building VSS. you can upgrade IOS of these switches before or after configuration of VSS, I prefer upgrade it one by one before VSS configuration. Once you build the VSS, HSRP is no longer needed you can remove HSRP configuration and configure Multi-chassis ether channel to connect end points devices as both switches virtually treats as single box.
Plesse follow these steps and connect the cables as given in below example
STEP1: Assigning Virtual Switch Domain and Switch Numbers
SW1(config)#switch virtual domain 1
SW1(config-vs-domain)#switch 1
SW2(config)#switch virtual domain 1
SW2(config-vs-domain)#switch 2
STEP3: Configuring Switch priority
Both switches are configured to use virtual domain 1, SW1 has been configured as “switch 1” and SW2 as “switch 2”. The next step is to assign a priority to determine what switch will become active or standby.
SW1(config-vs-domain)#switch 1 priority 110
SW1(config-vs-domain)#switch 2 priority 100
The higher the priority, the more likely you will become the active switch. Switch 1 will have a priority of 110, and switch 2 a priority of 100. This means SW1 will become the active switch.
STEP3: Configuring VSL Port Channel and Virtual Switch Link
You can use a single physical interface for VSL or create an etherchannel for redundancy
SW1(config)#interface port-channel 1
SW1(config-if)#no shutdown
SW1(config-if)#switch virtual link 1
SW1(config-if)#exit
SW1(config)#int range ten 1/4 - 5
SW1(config-if-range)#channel-group 1 mode on
SW1(config-if-range)#no shut
SW2(config)#interface port-channel 2
SW2(config-if)#no shutdown
SW2(config-if)#switch virtual link 2
SW2(config-if)#exit
SW2(config)#int range ten 1/4 - 5
SW2(config-if-range)#channel-group 2 mode on
SW2(config-if-range)#no shutdown
STEP4: Converting the Switch to Virtual Switch Mode:
SW1#switch convert mode virtual
Do you want to proceed? [yes/no]: yes
SW2#switch convert mode virtual
Do you want to proceed? [yes/no]: yes
The switches will then negotiate on the VSL to see which one becomes active or standby. As expected, SW1 is the active switch.
Verification
SW1#sh switch virtual
SW1#sh redudency
dual-active detection configuration
switch virtual domain 1
dual-active detection fast-hello
interface GigabitEthernet1/2/3
description “to SW2 gi2/2/3”
no switchport
no ip address
dual-active fast-hello
!
interface GigabitEthernet2/2/3
description “to SW1 gi1/2/3”
no switchport
no ip address
dual-active fast-hello
Hope this will help.
Regards
Shambhu Kumar
