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Andy White

Upgrading IOS 12.0 to 15.0 on 2960 and 3560 help?


It seems my 2960s and 3560s switches have enough flash space and memory to support the 15.0 IOS shoudl I be ok to jump to this from 12.2(35)?


Leo Laohoo
VIP Community Legend

Upgrade to 12.2(55)SE6 instead.  Avoid 12.2(58)SE and 15.0(1)SE because of un-resolved CPU bugs.  Avoid 15.0(2)SE as well.

Which CPU bugs are you referring to exactly? Because I upgraded a 2960S last week to 15.0.2-SE and it wouldn't boot anymore (Unexpected exception to CPUvector 2000). I RMA'ed the unit, the new one had no problems with the iOS 15 firmware.

Took the plunge and upgraded the 2 x 2960s and 2x 3560s to 15.0.2-SE and all seems good.

I believe CPU vector 2000 is a hardware issue.

The 15.0(2)SE1 is scheduled for release December 2012 but I think it's been pushed back.

Took the plunge and upgraded the 2 x 2960s and 2x 3560s to 15.0.2-SE

Try doing a TDR.  You'll get a surprise. 

(Heck, I've even posted the TDR bug on my blog.)

What run the copper test on either model of switch? 

Leo Laohoo
VIP Community Legend

5, 10 and 20 metres.

What is the exact syntax for that?

Leo Laohoo
VIP Community Legend

Which bit?  To run a TDR?

1.  Command:  test cable tdr interface ;

2.  Depending on the switch model, wait for 5 to 7 seconds (3560, 4500 and 6500 takes 60 seconds); and

3.  Command:  sh cable tdr interface


I ran the test cable tdr interface fa 0/1 on a trunk link and all was fine, this was on a 2960.  The CPU didn't flat line, did I do something wrong?  Or is it a hit and miss bug?


Leo Laohoo
VIP Community Legend

Hi Andy,

Do a "sh interface Fa0/1" (TIP:  Look at the status of your protocol) and/or "sh interface status".  Look what stands out.

Next, try a different length of cable.  Compare the the results.  Those are the bugs that we've so far found.