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I have a cable that when put into a switch seems to cause the entire network to crash -- however, only when put into a specific PC. When I'm trying the cable on another PC, I can't reproduce this. the cable is run through the wall, so replacing the cable is a hassle at this point unless I know it's the cable.
Is it possible for a misbehaving NIC or glitchy NIC to cause this issue? How can I diagnose this?
It actually crashes when the PC is OFF, when it's ON everything is okay..
Yes, it theoretically could, especially if your switch sucks. :) If you want to try a different cable with the suspect computer, it's probably easiest to move the suspect computer closer to the switch to try different cables. – Ƭᴇcʜιᴇ007 – 2014-01-21T17:13:07.297
@techie007 Moving the PC is a bit troublesome, but it'll defintely be easier than moving the cable. :) – Vaughan Hilts – 2014-01-21T17:15:35.333
When you say (in other comments) that's it's only doing it while it's OFF, do you mean Soft-off, or does it also do it when the computer is REALLY off (like unplugged from mains power). Have you ensured the RJ-45 jack/pins on the NIC aren't physically damaged? – Ƭᴇcʜιᴇ007 – 2014-01-21T17:57:01.983
@techie007 This is soft off presumably (powered down by Windows). I haven't verified the NIC isn't damaged, but if I knew how to check, I would. I'll do a hard off and see. – Vaughan Hilts – 2014-01-21T17:58:52.950
It's easy to start, just use your eyes! :) Look into the jack -- are the pins touching, bent, full of crud, etc? Also, can you confirm the problem goes away if power is completely removed from the system (hard off)? – Ƭᴇcʜιᴇ007 – 2014-01-21T18:01:08.280
Looks like everything is okay here if I directly pull the power plug... BIOS doing something whacky? – Vaughan Hilts – 2014-01-21T18:02:02.937
1@techie007 Updating the BIOS worked. Funny, huh? – Vaughan Hilts – 2014-01-21T18:52:21.157
Weird for sure. Glad to know you got it figured out! – Ƭᴇcʜιᴇ007 – 2014-01-21T19:24:11.477
Could not only be the NIC, could also be services running on that NIC. What exactly is crashing? Are there any error-signs on the other computers? I'd guess it could be something like a dhcp broadcast storm or something. – Vanadis – 2014-01-21T17:31:39.043
It actually crashes when the PC is OFF, when it's ON everything is okay... weird. Is the BIOS swapping on some kind of service? – Vaughan Hilts – 2014-01-21T17:37:58.413
@VaughanHilts Well... leaving the PC On should fix the problem. – Vanadis – 2014-01-21T17:43:41.913
That would be logical... but it's a waste of power and does not solve the root cause. :) – Vaughan Hilts – 2014-01-21T18:05:43.333
@techie007 After a little bit more diagnosis, it turns out the real suspect was the Wake On LAN setting, see this thread for information: http://forums.anandtech.com/showthread.php?t=2334881 (Enabling ERP turns off WOL forcefully, why would WOL crash it.. oh well.)
– Vaughan Hilts – 2014-01-23T17:34:49.853