Installed RJ45 wall jacks...now network runs at 10mbps only

[Emmsys]

Hi!

I have a Linksys 4port router and my 2 computers worked fine running at 100mbps. Instead of having a wire run from my room to my brothers along the wall, we setup jacks (like telephone jacks but for RJ45 cable) and passed the rj45 cable through the wall. The computer that is plugged into the jack (which is linked to another jack which is plugged into the router) will only work if the network card is set as 10mbps full duplex instead of 100mbps full duplex. The jack says CAT5 on it and the wires seem right since I can connect to the net and stuff at 10mbps but as soon as I set the network card to 100mbps, the little "network unplugged" thing pops up. I tried passing a wire directly from this pc to the router and of course it works at 100mbps. I much prefer having the jacks since it looks "cool" but these jacks seem to be the problem. I called up a friend and he knows a company with a small network that has the same problem. I don't understand why these would be a problem since technically, these jacks just connect the wire from the PC to the wire from the router. The wire between the jacks is about 30feet so it can't be the length causing the problem since a 100baseTx can have a 328 ft cable. I'm completely stumped. If anyone has an idea why I can't run at 100mbps anymore or even suggestions to try in Windows (once PC has Win2k and the other was just upgraded (formatted and installed) to WinXp) then please help me! Thanks in advance!

Emmsys

 

[Russ]

Is the entire network wired to the same standard; 568b or 568a? Jacks crimped securely? Not too much lead in the wire? No cuts in the wire?

Russ, NCNE

 

[nettech98]

100Mb is much less forgiving about wiring anomalies than 10Mb. For example, I have seen a 'straight-thru' cable (not keeping twisted pairs together) work with 10Mb just fine, but 100Mb wont even get a link light.

Almost all jacks are marked with the colors, so be sure you followed the instructions exactly.

Are you using the same cable to plug into the jack that you used to connect directly? You are obviously using an extra cable from the other jack. Be sure the cables are wired properly by looking at the colors. They should be in order:

WhtOrn/Orn/WhtGrn/Blu/WhtBlu/Grn/WhtBrn/Brn

In other words, pins 1+2 are a pair, 3+6, 4+5, and 7+8. This is the quickest way to stop 100Mb from working. I'm sure someone here can provide a link to some nice color diagrams.

 

[igiveup]

Russ!!! YOU BUILT MY COMPUTER!!!! So how do you like the Tyan Tiger?

Ok, back to the thread. Just a couple of things, some of them probably not even relevant. Keep your wire away from florescent lamps, like the tube kind you find in an office. I know, you probably don;t have those, but......

Just a thought... Straight from the router to the other computer and everything is just fine. If you plug it into the connection you have in the wall it bombs. Make sure you have a link light on the router and the NIC. Check and doublecheck your wiring in the wall. I am 90% sure your problem is physical (your wiring). Check your punchdowns, your patch cables, and plug the cable into a different port on the router to make sure its not the router.

 

[bigshooter]

Wouldn't the quality of the jacks also be a concern? If they aren't cat5 rated or data grade rated or whatever wouldn't you ahve problems? I ran a t1 into a voice grade biscuit block and it worked ok, but it would only run 10mbps on our 100mbps network. I'm not the one who tested that, but I know that it's wired correctly, it's just cat3 rated or somethign liek that.

edit: I didn't mean the t1 would run 10mbps, I plugged the system that would later be connected to a t1 into our network to configure it, and it ran at 10mbps.

 

[ScottMac]

Yes, That's correct. EVERY component (even the litlle crimp-on ends) must be rated to at least Cat 5 spec for 100 meg. The plates, the cable the connectors..everything.

You also have to make sure that no more than 1/2" is unjacketed and/or untwisted. No bends in the cable sharper than a 2" radius, no crushing of the external jacket, no kinks, twists, or nick in the jacket.

There's lots of rules, these are the first set of "biggies."

FWIW

Scott

 

[Russ]

<< So how do you like the Tyan Tiger? >>



igiveup,

It rocks when it's not eating RAM. Fried three Crucial 256MB sticks so far. I've been working with Crucial's test lab guy trying to figure out what's going on (he's got similar reports in). Last change I made was yanking my 3Com NIC and replacing it with an Intel Pro/100. Strangely, he said he's found a correlation between the 3Com, the Tiger MP and failure of Micron RAM. Been 18 days since I changed the card, so far so good.

Russ, NCNE

 

[Kell]

Other things to add to the above:

Use solid cable if possible. Stranded cable is more flexible, but its electrical properties are pretty sad compared to solid cable, and in most wall jacks and many tips, stranded cable will just not make solid contact.

Btw, concerning your dual-CPU box...it looks like you're just using SCSI (rock on, bro!), so you might have the onboard IDE disabled. I'd suggest you re-enable it; a report at theinquirer.net suggests that a lot of 3com+Tiger/ThunderMP incompatibilities (and probably others as well) can be traced back to a bug that crops up when you disable onboard IDE.

 

[Russ]

<< suggests that a lot of 3com+Tiger/ThunderMP incompatibilities (and probably others as well) can be traced back to a bug that crops up when you disable onboard IDE. >>



Kell,

Interesting. Thanks for the heads up. I'll look at that for my next step if I fry a stick again. The history has been about 30 days or so before death, so if it makes it past that this time, I'll consider it solved. If not, I'll try re-enabling the IDE controllers. I'll also pass the info on to Crucial.

Russ, NCNE

 

[igiveup]

Sorry to hear about that Russ. Registered RAM isn't cheap. At least you aren't buying it at prices from 3 years ago.....although it looks to be moving that way again. Thank god its not moving fast.

I finally broke down and invested in a SCSI drive and controller. WOW. Programs load freaky fast, and I haven't been able to task this Cheetah X15-36LP. Wonder what this thing would do in a RAID 0 setup.......

Russ, how hot does your rig get? Motherboard temps? CPU temps?


EMMSYS: Any updates? What happened?