Always be sure to use the right ethernet cables!

[Dean Roddey]

Just on the "don't make my mistakes" front... A while back I move over to make my music computer my development computer (more power), and it's in the 'living niche' area while the other computer stayed back in the bedroom, along with the little test CQC system, Dune player, and Vonage adaptor, and printer. And I still have to use the bedroom machine sometimes because I casn't afford to upgrade all my programs to Win7/64 and run them on the new work machine.

I was just having endless wierd network issues and couldn't figure them out. I eventually decided it must be a Netgear switch going off the deep end. I have one little switch that the bedroom computer and printer (and anything I might be testing over there) are connected to. It connects to a larger switch over near the Dune, CQC machine, and VOIP adaptor. And that goes up to the other room to the switch/router.

I never lost connectivity from the work machine. But the stuff in the bedroom would lose connection regularly and I could only get it back by power cycling the larger router. Sometimes it would work most of the day, sometimes for ten minutes. It was driving me crazy.

Finally it turned out that I'd not used a crossover cable to connect the small switch to the larger, and the larger to the router. Why it worked at all, I don't know. But I snipped the cables and changed the ends around, and it's been totally solid ever since. I never suspected the cables because it would work for a while, then croak. It doesn't seem like it should have. And power cycling the switch would make it happy again for a while.

Oh well, live and learn.

[wuench]

Most devices today have a feature called MDIX that will detect if a crossover or regular cable is attached. If it was the wrong type and neither side had MDIX it wouldn't have worked at all, so likely it was just a bad termination.

Best way to detect a physical issue is to look for physical errors on the switch or NIC. On windows netstat -e, look for errors, on the switch side look for CRC errors. Usually these increase with load so if it is a lightly loaded connection you may not see any errors, but if you push it they might show up.

[Dean Roddey]

Maybe so. I did have to re-do the end to flip it. It sure looked like a good one (it's the transparent type connector so you can see if the leads are all the way into their respective slots. But I guess it could have been bad in some way.

[wuench]

I had a weird issue way back in the day where a customer was having all kinds of strange issues with his PC (mostly when running WordPerfect). I reinstalled the software, rebuilt the machine from scratch, finally called in for a hardware replacement. Issue was still there, eventually I discovered the file cabinet was on top of the ethernet cable.....

So I always check for physical errors when network weirdness occurs, that and duplicate IP addresses....

[kblagron]

I had bought a few crossover cables by mistake, and should of tossed them, but thought I might need them for testing purposes, and had the same dilemna. Now before I ever hook up a cable, I hold the two ends up and make sure the colors are the same across the 4 pair before I put it in use.