Hello Kesav!
I’ll try to answer your questions one by one below:
a) Why two virtual links need to be created? Is it that one virtual link is used for data traffic and one for management traffic? What is the benefit / use case of having two virtual links?
Actually, Rene has created only one virtual link and one port channel. It just happens that he named the port channel on SW1-VSS Po1 and the port channel on SW2-VSS Po2. They’re just two ends of the same set of physical links that form the port channel. The same occurs for the Virtual link. The end of the link on SW1 is called virtual link 1 and the other end of the same virtual link on SW2 is called virtual link 2.
b) Also you had responded to Ali’s question that we can use single port channel (Po12) and bind all interfaces in both the switches under this Po12. If so, can we have two virtual links binded under one Po12?
Rene clarifies this in his answer. The labels “1” and “2” can be anything on each end of the etherchannel (or of the virtual link for that matter). He suggested using Po12 on both ends. You can use whatever you like. If it makes more sense to you, use the same number on both ends.
c) Does the VSL link need to be trunk ? If it’s access port, how can it differentiate data traffic from multiple VLAN’s and management traffic?
This is a very good question. Actually, the answer is “it depends on the platform being used.” The good thing is however, that when you issue the switch virtual link command, the proper configuration for the platform is implemented, so you don’t actually have to configure the corresponding switchport command. For more information, check out this Cisco Support Community post: https://supportforums.cisco.com/discussion/12987876/vss-vsls-port-channel-interface-switchport-or-no-switchport
d) Does VSL link have to be only L2? Can we have L3 interface as well for VSL?
Again, this is automatically configured by the switch virtual link command. See the following quote from the above link:
The 4500x works asswitchportand the 6800 works only asno switchport.
e) There is no configuration mentioned regarding SSO? Do we have to configure SSO mode under redundancy or is that setup by default ?
SSO is not something you need to configure, it is the technology, or the method by which the VSL will operate when/if the active switch goes down.
f) Finally, do you have any reference post in your forum for understanding Quad SUP SSO feature & In – Chassis redundancy?
As far as I know, Quad SUP SSO is not yet included in the forum, but we’re working on it! In the meantime, you can take a look at this Cisco reference: http://www.cisco.com/c/en/us/products/collateral/switches/mgx-8800-series-switches/white_paper_c11-729039.html
I hope this has been helpful!
Laz