Ports in err-disable

[mulbreizh]

Hello,

I have 2 Cisco Stack switchs connect to 2 Aruba Stack Switchs.

On CIsco switch, i configured port-channel (also from Aruba switchs). Everything works very good.

But yesterday, i powered off the 2 Aruba Switchs and just after i powered on.

But after restart the ports didn't come UP, they stay shutdown. So i take a look on Cisco switch ports and i case see that ports was in status 'err-disable'. I just passed the command 'shutdown' on port-channel and 'no shutdown' and after that all ports was UP again.

But i don't understand why when i Power off Aruba Switchs, Ports on Cisco are err-disable ? what could be the cause ? it is normal ?

thanks

[Georg Pauwen]

Hello,

when the ports go in err-disable state, the log (sh log) should tell you the reason. If that output is still there, can you try to find it and post it here ?

[MHM Cisco World]

enable logging, console/monitor logging level 7 
then 

shut/ no shut the port (err-disable)

show logging 
you can detect what is the cause of err-disable 

MHM

[Jeff Sibal]

You may enable Errdisable autorecovery when Err-Disable occurs between your Aruba and Switch LACP or simply disable the etherchannel misconfig guard that are inherently enabled on Cisco Switch.

View all ErrDisable reason 
# show errdisable detect (all reasons are enabled by default)

View all ErrDisable Recovery status
#show errdisable recovery (all recovery are disabled by default)

It is helpful to verify the cause of Err-Disable state in Etherchannel from the show logging, then decide which among the auto-recovery to enable. This is keep you from manually bouncing the port gone on Err-Disabel state.

For above screenshot, I enabled the autorecovery when the Errdisable shown from the show logging is "channel-misconfig error detected"

Here is the complete CLI command to implement on Cisco Switch

#errdisable recovery interval 30
#errdisable recovery cause channel-misconfig

Furthermore, you may simply disable the etherchannel misconfig guard through this command.

#no spanning-tree etherchannel guard misconfig

I hope this helps.

Thank you