Quad sup VSS on a 6807-XL pair

[richard.schultz1]

Just curious because I can't seem to determine the answer from readings.

I understand that in a failure situation on Chassis A supervisor 1, Chassis B supervisor 1 takes over. However, what if Chassis A Sup 1 remains in a failed state and Chassis B Sup 1 fails? Does it then fail down to Chassis B Sup 2? Or does the entire thing go down?

[Reza Sharifi]

Have not tested this before, but this link shows the Z pattern switchover. So, it appears that if sup 1 in switch 1 fails, sup 1 in switch 2 will be active.  if sup 1 in switch 2 fails sup 2 in switch 1 will be active. and finally if sup 2 in switch 1 fails sup 2 in switch 2 will be active.

see figure-2

http://www.cisco.com/c/en/us/products/collateral/switches/mgx-8800-series-switches/white_paper_c11-729039.html

HTH

[Madhukrishnan Gopinathan Nair · Accepted solution]

Hi Richard,

i dont think the whole switch will go down since it falls back to Chassis A Supervisor 2 and Chassis B supervisor 2 will be VSS standby Sup and Inchassis active for Chassis 2.

Please read the Supervisor Switchover Events under the below link for a better understanding.

http://www.cisco.com/c/en/us/products/collateral/switches/mgx-8800-series-switches/white_paper_c11-729039.html

Hope this helps you. 

"Rating encourages particpation"

Thanks

Madhu.