3COM Switch dropping broadband

Question

We have a 3COM 3C16980A Superstack3 switch in our office and it keeps dropping out broadband connection. Are setup is this:

Internet -> BT Box -> Wifi Router -> Switch -> cables run into the walls to all the sockets round the office.

Several times now our switch has stopped serving out data, mainly in the morning but once in the afternoon. The wifi still works and I have connected a computer directly to the wifi router and that works, so it's only the switch which is blocking the connection.

We end up fixing it by switching it on and off several times, leaving it off for a while, or just waiting, nothing consistently works. My thoughts are that the switch is faulty but it is out of warranty so wanted to get a second opinion before recommending we get a new switch as they are expensive.

Additional switch details: http://h20566.www2.hpe.com/portal/site/hpsc/public/psi/home/?sp4ts.oid=4236314&sp4ts.pn=JE854A&sp4ts.sn=7MMV6E5CF38 http://www.zdtronic.com/images/3C16980A.jpg http://www.mtmnet.com/PDF_FILES/3C16980A_Datasheet.pdf

Answer 1

Your switch is old.

Replace the switch.

The device went End-of-Sale in 2004. That's 11 years ago. There's no reason to be running a critical device that old without support. Plus, it's 10/100 Megabit.

You could look at the front panel and see if there are any error lights. Switches like that can have fan failures. But it's not worth repairing.

A decent replacement switch from HP could be found as low as $350 in the HP 1820 switch series.

Answer 2

Could it be that the switch is set up to use Spanning Tree Protocol (STP)?

3com has a broken implementation on some older models that will stop forwarding packets for two minutes whenever a link goes up. That bug is fixed in more recent firmware, but might explain why it happens often in the morning (when people turn on their computers), and seldom in the afternoon (when someone who was just leaving needs to look up something quickly and turns the computer back on).