Lost the network???

[crtlaltdel]

Well, It is starting to look the hub could be bad, I would change the nic speed to 100mps and try running them at half-duplex and see what happens also try auto settings too

[BurnFEST]

Originally posted by Deity:
Another system went down today. Just as I walked in the door, our legal person said her system stopped responding. Same situation. Different brand network card too. Her system ran fine for about 48 hours, only to drop suddenly from the system.

Yeah its starting to seem like it might be the switch that's at fualt here. Have you tried changing the port in the switch for the problem system. I had a similar broblem a few weeks ago and to fix it a just swapped the computer to a different port on my hub.

[BurnFEST]

Oh yeah, i left this out. Is the problem occuring on only one of the two switches or both?

[KINGofBLEH]

It sounds like a cabling issue or a bum switch. If you have not done so, invest in a good sniffer or cable tester. There may be slight voltage fluctuations in the cables/connectors. Or you may have a damaged pair which do not show up until you change speeds. A good cable tester will even tell you which pair is faulty and why.

If you are running wall jacks with patch cables connecting them to the punch-downs or hub/switch, the recommended maximum cable length is 295 feet. This was determined a few years ago in preparation for the 100Mbps transfer rate. If you exceed this limit, you run the risk of poor/no response from the line. I think the length limit for standard Cat 5 (from the puter to the wall jack) is 100 feet. I could be wrong on that though.

I would also try swapping another machine that is known good to one of the problem jacks just to make sure that it is not an OS problem or an issue with the network stack.

[BurnFEST]

Are you using UTP (unshielded) or STP (sheilded) CAT5 cable through the walls? If youre only using UTP, u could be getting interference.

[Deity]

I'm pretty sure it's not the cabling or the switches. For testing purposes, I moved one of the problem systems into the server room and connected it with a 5 foot patch cable. It had the same issues. I also tried several different ports on the both switches, with the same results everytime. All the cabling in the office is under 150 ft in length and all a straight connection between the switchs and the systems.

[tk421]

have you tried testing the cabling between the switch and the problem machines by connecting them with a different cable?

[BurnFEST]

Originally posted by tk421:
have you tried testing the cabling between the switch and the problem machines by connecting them with a different cable?

From the post before, it sounds like he just tried that.
It must be a compatibility problem between the network cards and the switch. Have you tried a different card / working of the same type of card in the problem systems?

[Deity]

Yesterday I tried a new NIC, but it was the same brand...it worked for about 10 mins just fine, then quit with the same symptoms.

I just tried a different brand card, and it seems to work so far, but I guess only time will tell.

[tk421]

Originally posted by BurnFEST:
From the post before, it sounds like he just tried that.

ahh, you're right. I missed it.

well it looks like you're on the way to getting it. It's either NIC incompatibility, or it's the hub.

[Deity]

Well, it's been three days with the new NICs and they are still running perfectly. *knock on wood* It must have been something about that brand of network card that didn't work well.

Thanks everybody for your help.

[Higg]

A little note for this: once-upon-a-time when I began IT-working I was responsible for a PC/UNIX-net... I forced to use NIC's from SMC as they had been common to me - but I found out, that problems on some PC's (slow booting, netware login not available, etc...) disappeared at that moment I used a different type of NIC...

After that I never used SMC's again - even if I beleive that they couldn't be bad... but those we owned had been a pain for a long time (you need time to find out, why things only work sometimes

good luck now... Higg

[gren]

I'm sure you've done this 100 times, but check the pinning on the rj45 connectors. Make sure they're pinned for 10/100 mbps compatibility. Old cat 5 were just pinned for 10.. Can't remember the exact pinning on the top of my head, been a little while since I crimped a cable. If you have a wire continuity tester, that'd do the job. And.. if that's not it, are there any firmware upgrades on the switches?

[gren]

That's what I get for reading page 1 and haphazardly responding. Felt kinda silly when I responded and looked.. "oh.. there's a page 2.." damn. Disregard my post.