err-disabled bpdugurad

[rajive.rehan]

            how to recover from eer-disabled bpduguard switchport

[Leo Laohoo]

conf t

interface

shut

no shut

end

[rajive.rehan]

but what if ports again goes in errdisabled mode..

[Jan Hrnko]

Hi Rajeev,

The best thing you can do is to fix the problem. But if you want to - you can set automatic recovery for all or only some causes.

You can use this command for automatic recovery in case of bpdu guard :

Switch(Config)#errdisable recovery cause bpduguard

And you can adjust the timer settings for recovery ( interval is in seconds ):

Switch(Config)#errdisable recovery interval <30-86400>

For example executing these commands:

Switch(Config)#errdisable recovery cause bpduguard

Switch(Config)#errdisable recovery interval 30

Will adjust recovery from errdisable state in such a way that the port put in errdisable state by bpdu guard will recover in 30 seconds. 

Best regards,

Jan

[rajive.rehan]

Hi Jan,

thanks for your comments.

can you please let me know what could be the cause, as the device which is attached on the errdisable port is a server.

regards

Rajeev

[Jan Hrnko]

Hi Rajeev,

sure. How often does it go to the err-disable state? Immediately? I am thinking what could trigger such an event. Server should not generate any STP messages - and I think that this is the case - BPDU guard is used upon receiving and STP message on a portast enabled port.

Best regards,

Jan

[Jan Hrnko]

Hi Rajeev,

one more thing. Isn't there any bridging software on the server? What kind of server is it? And the last thing - try to check the physical layer - if cabling is ok or if the server is DIRECTLY connected to the SWITCH or if there is another device between.

Best regards,

Jan

[Leo Laohoo]

If you want to know the cause of the error disable, then enter the command "sh interface status err".  If you have error disable caused by BPDU guard then this means that your switches have enabled a BPDU guard safety feature and someones's plugged a layer 2 device on this port.

[jazzman20014]

If you want to see what is really going on with the port the best command that I have found is:

show controllers ethernet-controller

Transmit GigabitEthernet1/0/1            Receive

            0 Bytes                                0 Bytes

            0 Unicast frames                       0 Unicast frames

            0 Multicast frames                     0 Multicast frames

            0 Broadcast frames                     0 Broadcast frames

            0 Too old frames                       0 Unicast bytes

            0 Deferred frames                      0 Multicast bytes

            0 MTU exceeded frames                  0 Broadcast bytes

            0 1 collision frames                   0 Alignment errors

            0 2 collision frames                   0 FCS errors

            0 3 collision frames                   0 Oversize frames

            0 4 collision frames                   0 Undersize frames

            0 5 collision frames                   0 Collision fragments

            0 6 collision frames

            0 7 collision frames                   0 Minimum size frames

            0 8 collision frames                   0 65 to 127 byte frames

            0 9 collision frames                   0 128 to 255 byte frames

            0 10 collision frames                  0 256 to 511 byte frames

            0 11 collision frames                  0 512 to 1023 byte frames

            0 12 collision frames                  0 1024 to 1518 byte frames

            0 13 collision frames                  0 Overrun frames

            0 14 collision frames                  0 Pause frames

            0 15 collision frames

            0 Excessive collisions                 0 Symbol error frames

            0 Late collisions                      0 Invalid frames, too large

            0 VLAN discard frames                  0 Valid frames, too large

            0 Excess defer frames                  0 Invalid frames, too small

            0 64 byte frames                       0 Valid frames, too small

            0 127 byte frames

            0 255 byte frames                      0 Too old frames

            0 511 byte frames                      0 Valid oversize frames

            0 1023 byte frames                     0 System FCS error frames

            0 1518 byte frames                     0 RxPortFifoFull drop frame

            0 Too large frames

            0 Good (1 coll) frames

            0 Good (>1 coll) frames

The bottom right of the output gives you an idea of the issue and the Cisco site will detail what the likly cause is.

Not tried this but I guess it would give you this issue - a VM Host that is connected in this way may error disable a BPDU protected port as the BPDU packets are exchanged between switches (VM would have a virtaul switch) and could disable the port?

Hope this helps

Matt