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