We're Sorry, Full Content Access is for Members Only...

If you like to keep on reading, Become a Member Now! Here is why:

  • Learn any CCNA, CCNP and CCIE R&S Topic. Explained As Simple As Possible.
  • Try for Just $1. The Best Dollar You've Ever Spent on Your Cisco Career!
  • Full Access to our 651 Lessons. More Lessons Added Every Week!
  • Content created by Rene Molenaar (CCIE #41726)

451 Sign Ups in the last 30 days

100% Satisfaction Guaranteed!
You may cancel your monthly membership at any time.
No Questions Asked!


Forum Replies

  1. Hi Rene,

    I’ve been going through your other posts and it’s really great. Also i was searching for VPC related links in google and it ended up 404 page.


    Can you share me new links where i can go through regarding VPC member ports, peer link and traffic flow with an example ?

  2. 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

    ... Continue reading in our forum

  3. Hi,

    Rene If a switch is connected to VSS enable switch ( redundant connectivity switch 1 and switch 2 ) and RSTP is running in this case
    who will be the root bridge ?


  4. Hi Abhishek,

    If your VSL fails then the standby switch can’t tell if the active switch is still there or not. If the standby switch goes active while the active switch is still there, both will be active, forwarding packets and you’ll run into issues. This is called “dual active”.

    Dual-active detection is configured outside of the VSL link. There’s enhanced PAgp, BFD and Dual-Active Fast Hello Packets to use. You can use one or all three at the same time.

    Cisco has a pretty good document for this:


    ... Continue reading in our forum

  5. Hello Helen

    The use of two or more links for the Virtual Switch Link (VSL) is only a recommendation by Cisco. It is not manditory. However, this is not recommended as VSS is designed to be a high availability system and by having only one link, this high availability is sacrificed. It should be implemented fully realising this. Ideally, you should purchase an additional module to implemente multiple links.

    I hope this has been helpful!


43 more replies! Ask a question or join the discussion by visiting our Community Forum