We tossed switches out years ago because we couldn't afford the downtime. In fact we can't afford to troubleshoot if a dumb hub is the issue. I'm sure you need to re-evaluate keeping possibly failing hardware.
They used to call them network storms when they didn't understnad what the cause was. Its usually a WORM or failed hardware.
We are having some very occasional but weird connectivity problems with our network. Here are the issues:
1) Server is Small Business Server 4.5 (NT 4.0). Yes, I know it's old and soon to be not supported, we have plans to replace, but please read on, I don't think this is the problem.
2) Most workstations are Win 98 SE, a couple are Win XP Pro.
3) If no activity on the network (i.e. over the weekend...but we leave the server on so that incoming Internet emails don't sit in queue and come in), eventually (i.e. first thing Monday morning) the workstations cannot log in, says "no domain server available"
4) Rebooting the server almost always fixes this, but I found a workaround anyway. If I leave my workstation on overnight/weekend and have it constantly ping the server, the "disconnect" doesn't happen.
5) Despite #4 above, on two different occasions last week, someone could not boot in from their workstation, getting the "no domain server available" message, even though others in the office could. In one instance, it was one of the Win 98SE workstations, in the other it was one of the Win XP Pro ones. Rebooting the server fixed this.
6) I was simply reaching for something behind the server when suddenly the network went down. I looked and no wires or anything were loosened, etc. When I rebooted the server, still no one could get in. I shut off and restarted our hub, still no one could get in, but when I then rebooted the server, they could get in.
7) For about 15 minutes after people got in our hub was wild with activity and people had a very slow time getting on the network, opening their email, surfing the Web, etc, but then suddenly it quieted down and all was fine. Keep in mind that it is not because 15-20 people were going in at once because that is no different that 8:30-9am on a typical morning here.
My suspicion is that the problem is our ancient (8 years old) hub and its time to replace with a nice switch, but I wanted to get any thoughts you may have, thanks.