3524 with 3550 stack problems

[crispopa]

Hello,

I have a stack with a mixture of CISCO switches: 2x3508 + 2x3524 + 1x3550. It is working.

The problem is that I need to add another 3550 in stack and when I am doing that, the old 3550 stops responding to the network. GBIC ports for both 3550 are configured with "nonegotiate". actual 3550 is reporting for stack module : half-duplex - 1000Mb/s.
When I am connecting the new 3550 : the old 3550 stack port is going automatically to full duplex and I can not do anything to keep it half.

Both 3550 are running SMI images: 121-8.EA1c.

Does someone seen this before?
Can someone help me?

(I do not have budget to change whole stack...)

Regards,

 

[baddos]

12.1.8 is pretty old... Try upgrading to the latest 12.1.14 and see if it fixes that problem. Upgrade both the new and the old 3550s to it.