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Virtual Connect & Cisco Virtual Switching System (VSS) Cabling Question

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Virtual Connect & Cisco Virtual Switching System (VSS) Cabling Question

Aniekan was looking to validate a configuration:




Can we setup a Virtual Connect ànd a Cisco VSS with just one uplink port from VC to Cisco VSS switch?


Here’s the scenario. We designed this solution for a customer last year: 2 x c7000, 2 x (VC Flex-10 + VC FC) per enclosure, A/A SUS uplink, upstream Cisco switches (Production SW-x):






The above environment has been running for a year.

Note: The dashed lines do not exist, only recommended.


The customer is now ready to migrate to a single logical switch configuration (i.e. VSS). We are proposing the following cabling changes, with no changes to VC config:





Customer wants to do this in two steps:

  1. Above configuration with only a single uplink port per VC module (i.e. without the dashed lines)
  2. At some time later, add the 2nd uplink ports (dashed lines) per VC module


Out of an abundance of caution, I want to confirm that it will work, even if it is not a best practice.




Input from Lionel:




This scenario is called Dual Homed Active/Active (versus Single Homed). It’s in fact a VC best practice and is usually recommended for its higher availability. It works well and is the recommended design when VSS/vPC is available. If you have a maintenance or failure (this happens sometimes when using Cisco J ) with one of the Cisco switch, Smartlink is not triggered, all server downlinks stay up, therefore no NIC failover takes place and no server SNMP alarms are sent.




Any other comments or suggestions?