2960X Stack LACP to DELL issue

[i.leridant]

Hi everyone,

I've a WS-C2960X-24TD-L (let's call him the firest one) working fine with LACP to Cisco device and DELL device.

It was working fine.

To prevent a SPOF, my customer bought an other (the second one).

I've configured a stack between the coupe of WS-C2960X-24TD-L.

With no interface configured everything's fine.

I bundle a pair of TenGig to the Cisco 4500X (VSS), the sky is still blue.

I start to bundle my gig interface linked to a DELL fabric and this is bad : each switch remove the other from the stack and this sample of messages appear : 

Sep 7 15:32:55.730: %EC-5-L3DONTBNDL2: Gi1/0/2 suspended: LACP currently not enabled on the remote port.
Sep 7 15:32:55.824: %EC-5-L3DONTBNDL2: Gi1/0/15 suspended: LACP currently not enabled on the remote port.
Sep 7 15:32:56.083: %EC-5-L3DONTBNDL2: Gi1/0/16 suspended: LACP currently not enabled on the remote port.
Sep 7 15:32:56.656: %LINK-3-UPDOWN: Interface Port-channel3, changed state to down.

I break the stack, reload the first one and it's working again.

I put again the stack and start the second one and boum, the same logs and erros appears !

Has someone an idea ?

[Reza Sharifi]

Hi,

Have you tried the same config but with no LACP (mode on)?

Are you connecting the stack of switches to one server?

HTH

[i.leridant]

Hi Reza,

I am connecting the stack to 4 DELL powerconnect I/O module running LACP on their uplink to my stack.

The originale configuration is LACP for both and when my first switch is standalone there is no issue.

When I set up the stack, my first has still every connection and after 2 minutes the stack is broken : on each the other stack member is seen "removed".

I shut every interface of the stack (1/0/1 - 24 and 2/0/1 - 24 + my 4 Po), I configure correctly the second one's interfaces in order to change connections, and reload the two switches.

Then everything is fine.

i "no shut" the Po to activate my interfaces 2/0/1 - 16 then 2 minutes later I have the same logs, on the second switch of the stack, and each other is removed of the stack.

I remove the LACP conf and put "mode on" and I have the same issues for each case.