I thought this was a four port hub? If it has 5 jacks on it, I think you'll find that one 'port' has two jacks, standard and cross-over. You can only use one of those jacks at a time. RTFM the hub docs and make sure you know how to plug it together. And as Toby said, you need to get anal. Such as swapping other machines onto the suspect port and find out, is it related to the port or to the machine? Swap cables to make sure it isn't a bad cable. Try at least a significant fraction of the possible machine/port combinations to make sure it isn't NIC/port related. You aren't in anal territory by a long shot yet. Hattie Rouge > -----Original Message----- > From: psyche-list-admin@xxxxxxxxxx > [mailto:psyche-list-admin@xxxxxxxxxx] On Behalf Of Toby > Sent: Sunday, May 25, 2003 8:28 PM > To: psyche-list@xxxxxxxxxx > Subject: Re: Nasty little network problem > > > Harry Putnam wrote: > > Michael Schwendt <ms-nospam-0306@xxxxxxxx> writes: > > > > > >>>Plug them back into hub1 and they can't even with switching around > >>>port holes and cables. > >> > >>What happens if you pull M3 and M4 from hub1 instead? > >>Just curious. > > > > > > Haa... hadn't thought to try that, but that would eliminate anything > > weird the gateway might be doing. But no, no such luck. > > > > Putting M2 back on original hub1 and unplugging M3 M4. M1 and M2 > > cannot communicate. So it seems like evidence is telling me that > > something about hub1 is unacceptable to the NIC on M2. > That something > > isn't present on hub2. > > > > Not impossible. Reminds me of the problem I had with rh7.1, > 3c905c nics > & netgear ds16 hubs. The nics kept flipping back and forth > between 10 & > 100 Mb while the hubs stayed at 100Mb. When I brought in > fully switched > equipment, the win installs started balking on identical pcs. > > > > The configuration that is working right now. Allowing full > > communication is: > > > > M1 M3 M4 on HUB1 M2 on HUB2 which is uplinked to HUB1 > > > > > > > You're going to have to get anal methodical here and > eliminate things. > Assure yourself that similar components work similarly. > > hub1 seems suspect. Are the hubs identical? Swap hub1 for > hub2 entirely. > If M2 really has a problem with hub1, then I would expect M2 > to not work > plugged into hub1 cascaded into hub2 into M5. > > If M2's nic really has a problem with hub1, then I would > expect M3 with > M2's nic would have the same problem. > > Autosensing? Try locking down the speed. Reverse the hubs & > test again. > > Don't know your nic make, but you can monitor 3com cards with > mii-diag ( > I believe it's called that) > > Eliminate bad cables/wiring. Swap around all the patch cables > themselves, keeping tabs of origins. > > How about in the wall wiring? If you're using it, eliminate it as a > problem. Move the machines around. > > Check the logs for suspect nic/network info. > > Use tcpdump to watch traffic. > > -toby > > > -- > Psyche-list mailing list > Psyche-list@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/psyche> -list > -- Psyche-list mailing list Psyche-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/psyche-list
