BL495c G5 link-flap err-disable on cisco 3020

[brice-a]

We have 4 BL495c blades, which of course include 10gb nics on the baseboard. Also, we have a 2 port fiber module in mezzanine 1, and a quad 1gb nic in mezzanine slot 2 (however we don't have enough switches to use the last 2 ports).

During a reboot, we get enough link-flap messages to cause the cisco 3020 to set the ports to error disable. This is happening on every blade and across 2 switches. It only happens to the 10gb nics. These two port map to interconnect bay 1 and 2, and in both we have cisco 3020 switches. We changed the link-flap from the default of 5 in 10 seconds to 10 in 10 seconds which resolved the issue -- however we do not view this as a permanent fix. Any thoughts?

Btw we tried every combo of auto negotiate and statically assigning speeds -- none of that really matters, because this happens during a reboot at the instant the blade 'restarts' just before the white proliant bios splash.

[Lmm_1 · Accepted solution]

I was able to fix this issue by upgrading the IOS to version 12.2(50)SE1, however release notes for that IOS doesnt mention this issue.

[brice-a]

Updating the IOS corrected the issue for me as well. Awesome.

[BeltwayBenny]

this will help on the current IOS if you can't upgrade:

errdisable flap-setting cause link-flap max-flaps 10 time 10

[BNewby]

Did we ever get a root cause on this issue? Generally we want to know WHY it is happening before we increase the value. We are seeing the same issue on bl460c g6's. They are booting up normally and shouldn't be flapping for any reason. This is happening only on our "secondary" 3020 or Interconnect bay 2 on a c7000. Interconnect bay 1 isn't error disabling the port for some reason.

Thank you in advance.

[Lmm_1]

It is normal to sense flaps during boot, now the Flex10 LOMs are totally different architecture (4 NICs on each port), which is causing the switch to detect the required amount of flaps to put the interface on err-disabled state. New IOS will not monitor link-flap on internal interfaces since there is no need (Interfaces intended to servers, STP disabled), therefore the NICs will work just fine

[Magnus von Rosen]

I LOVE YOU! Well, not like that...
This solved it for me as well. Almost 2 workdays of dispair!