Power loss - Holdup time on 2960

Unanswered Question
Dec 13th, 2007

Does anyone have information on how many ms a Catalyst 2960 can stay running without power before rebooting? (Seems that the power supplies for 4500 etc can manage 20 ms.) I have a potential loss of power for 3-5 ms, and would like to manage without an extra UPS for this.

I am not really sure which forum this question should be addressed to...

I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
irisrios Thu, 12/20/2007 - 06:55

I'm not sure about the holdup time . But it is for sure that 3-5 ms doesn't matter. If the hold time had been less 3-5 ms you won't be able to see the LEDs as soon as power cable is unplugged. Whereas in releaity when you plug the power you can actually see LEDs going down .

danieldahlberg Thu, 12/20/2007 - 07:52

I am aware that this is what it is like in practical life, but I need it written in some Cisco datasheet etc.

andrew.burns Fri, 12/21/2007 - 04:28


Sometimes the info is added to the data sheet and sometimes not. It looks like for the 2960 it's not published - however if you ask Cisco they're normally pretty good at providing this kind of info.

The RPS 2300 power supplies (which are compatible with the 2960) have a holdup of 20ms (except the DC ones which only get you 2ms) so I'd expect a similar number from the actual power supplies.



danieldahlberg Fri, 12/28/2007 - 04:50

Yes, I expect something like that, but the problem is to get the info from Cisco. Do you have any suggestion on who/how to contact?

andrew.burns Fri, 12/28/2007 - 08:31


I'd ask my account manager to get me the info in the first place, although if I needed the info quickly I might also raise a TAC case.



danieldahlberg Tue, 03/11/2008 - 02:29

Well, the answer I received was that they thought it was around 4 ms, but could not confirm it.

For the 4507 power supplies, however, Cisco states 20 ms holdup time.


This Discussion