Emergency help - Sup 720 & Sup 720-3B

Answered Question
Jul 23rd, 2009

I hope this can be done. We have a Cat 6500 with a Sup 720 (PFC-3a) that is starting to show signs of failure. Show module is already reporting that it has failed, but is only now starting to cause problems.

I have only a single Sup 720 (w/ PFC-3a) installed in the chassis. My question - I have a Sup 720-3B sitting in the box. Can I just pop this module in and will it interoperate with the PFC-3a? My hope is that I can simply pop it in, sync the config and then remove the bad sup for repair.


I have this problem too.
0 votes
Correct Answer by Jon Marshall about 7 years 6 months ago


Unfortunately you can't do this. The PFCx and MSFCx versions must be identical in each supervisor -

"Likewise, the PFCx and MSFCx versions must match on the active and standby Supervisor Engine 720 or Supervisor Engine 32"

Full link -



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Overall Rating: 5 (1 ratings)
jim_berlow Thu, 07/23/2009 - 10:05

Thank you for your help, Jon.

I'll just have to wait for the replacement part from Cisco TAC.


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