Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have a pair of 3Com 4200 Superstack III switches stacked together. One is a 4226T and the other a 4228G. The only real difference is that the 4228G has two ports that I can use for fiber connections (one of which is occupied for a link over to a different building). The 4228G is unit 1, and the 4226T is unit 2.

Today, for some unkown reason, I can no longer see unit 2 in the stack. I can move the stacking cable back and forth to swap unit numbers, and both ends will use the new number. So something is working. But anyone plugged in to the 4226T can't see the rest of the network, and both the web and telnet administration interfaces from the 4228G now just show a single unit.

Any ideas what might be going on?

share|improve this question
up vote 1 down vote accepted

I've had experience with older 3com Superstack II switches, where the weight of the stacking cable (or other cables draped over it) pulls on the port and eventually it goes bad. I've also seen stacking cables that eventually just fail. Try using the other stacking port with a new cable.

In the short-term, a cross-over cable between the switches will get your users back up and running.

share|improve this answer
Already tried a new cable and the other port. I went back an hour later with a cable to just connect them and the other unit was back online. – Joel Coel Sep 30 '10 at 13:11

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.