Port-channel problem - %EC-5-UNBUNDLE cisco 4507 (Sup 7L-E)

[baynazarov.almat]

Hi, 

Last month we have this error in our cisco log:

133937: .Nov 30 08:57:15.071: %EC-5-UNBUNDLE: Interface Gi7/4 left the port-channel Po1
133938: .Nov 30 08:57:18.733: %EC-5-BUNDLE: Interface Gi7/4 joined port-channel Po1
133939: .Nov 30 08:57:45.071: %EC-5-UNBUNDLE: Interface Gi7/4 left the port-channel Po1
133940: .Nov 30 08:57:48.742: %EC-5-BUNDLE: Interface Gi7/4 joined port-channel Po1
133941: .Nov 30 08:58:15.071: %EC-5-UNBUNDLE: Interface Gi7/4 left the port-channel Po1

If I will not respond on this massage, portchannel will go down in newar 30 minutes. 

This connection worked perfectly for 2 years, but now suddenly started to go down. Po1 and Po2 are responsible for hyper-v server bease on 2012r2, conected as LACP. First time this error accured on Po2. I thought that it is server problem and migrated all the servers on another, which is Po1. But problem migrated too =) 

1. To exlude layer 1 problem, I have changed all 4 cables. Also migration excluded ethernet adapter of the server and system OS. 

Here is my config:

interface Port-channel1
switchport
switchport mode trunk
end

interface GigabitEthernet7/2
description DBS1 Portchannel 1
switchport mode trunk
channel-protocol lacp
channel-group 1 mode active
!
interface GigabitEthernet7/3
description DBS1 Portchannel 1
switchport mode trunk
channel-protocol lacp
channel-group 1 mode active
!
interface GigabitEthernet7/4
description DBS1 Portchannel 1
switchport mode trunk
channel-protocol lacp
channel-group 1 mode active
!
interface GigabitEthernet7/5
description DBS1 Portchannel 1
switchport mode trunk
channel-protocol lacp
channel-group 1 mode active
!

Does anyone know why this error accurs? 

[Mark Malone]

Are you seeing any errors increment on the physical interfaces of the port-channel for that port 7/4

instead of LACP incase its a protocol issue have you tried force the po with mode on

is it continually happening or only last month once off

[baynazarov.almat]

No error on physical port gig 7/4.

I didn't try "mode on" option

It started to happen last month. and happens periodically. It can work day, but then will sudden go down after lots of error messages in log.

[Mark Malone]

If its happening periodically and there is no reason you could have triggered a bug in your ios version , I would test the on mode see if that fixes it if not you could move to another ios verion , have you checked year release version online to see if there are any bugs related to the current version with LACP that your using

[baynazarov.almat]

I have checked release notes, but couldn't find any updates associated with etherchannel or lacp protocol.

I will try to update supervisor engine to newest version soon, because I couldn't find any other way to solve this issue.