network cable length

[joshmac]

hello guys and gals,


i used to be able to connect worskstations to a domain using considerably long cable length (under Windows 2k3). This is without internet connection.

But this time, with internet connection, i can no longer connect workstations using the same cable lengths before the internet connection. I'm able to connect PCs with shorter cable length though.

It would seem to me that the internet connection has somehow shortened the connectivity capability (signal) of the network.

Is this supposed to happen? What can i do? Please help. Thanks.

[berrybry]

the 802.3 standard has a max cable lenght with out a repeater i want to say 100m. After this length the protocol can not detect collisions. Also what are you conneting together and with what types of cables? For example A windows XP computer to a net gear switch to a D-Link router with cat 5 cable. The model of switch and other equipment is also helpfull. Also make sure you are not using a cross over cable unless you are going same device to same device (router to router, switch to switch, computer to computer etc)

[YeOldeStonecat]

Hard to say if you were actually able to connect them to the domain before...even if network connectivity was lost, Windows NT based workstations will cache the domain credentials locally (hence the reason you can take a laptop away from the domain, take it home, and appear to still log into the domain).

Were you actually able to see file shares on this domain? Print to printers?

What tells you you can't connect to the internet? Is DNS setup correctly? Can you ping public IP addresses and get replies?

[joshmac]

Thanks for the reply guys. I appreciate it.

I'm actually able to connect them to the domain. Before the internet connection, i can still see and access file shares and print to printers.

DNS was setup correctly, I've been reading your articles. Thanks.

Before the internet connection, the domain was fine. Now, with the internet connection, i'm still able to connect to the internet (ping public domains and get replies) but this is however somehow limited to cable length. There are no problems with workstations which are near the switch. The ones connected farther away (less than 30 meters) could not connect to the internet.

I'm using a 3COM switch and a LinkSys BEFSR41 router and CAT5 cables.

Hope you could reply again. Many thanks.

[joshmac]

Thanks for the reply guys. I appreciate it.

I'm actually able to connect them to the domain. Before the internet connection, i can still see and access file shares and print to printers.

DNS was setup correctly, I've been reading your articles. Thanks.

Before the internet connection, the domain was fine. Now, with the internet connection, i'm still able to connect to the internet (ping public domains and get replies) but this is however somehow limited to cable length. There are no problems with workstations which are near the switch. The ones connected farther away (less than 30 meters) could not connect to the internet.

I'm using a 3COM switch and a LinkSys BEFSR41 router and CAT5 cables.

Hope you could reply again. Many thanks.

[koldchillah]

Did you buy the cables pre-made, or make your own?

For less than 30 meters there is no reason it should work any differently than the shorter cables unless the cable is bad or there is some form of interference causing distortion or cross-talk.

[joshmac]

Thanks for the reply.

You're right, there should be no problem if its only less than 30 meters. Perhaps there might be some sort of interference. I'll be looking into that.

I didn't buy the cables. Just crimped them myself. I'll be checking on the cables again, just in case. But i'm quite confident its not the cables. Done testing on them several times already.

Without the internet connection, connecting to the domain using longer cables is not a problem. Should i perhaps try to update the router firmware? (Linksys BEFSR41)

Thanks again.

[YeOldeStonecat]

I didn't buy the cables. Just crimped them myself. I'll be checking on the cables again, just in case. But i'm quite confident its not the cables. Done testing on them several times already.

Hmmm...

What are you testing with? Just a linklight? (useless as can be IMO) Or a nice professional tester, like a Fluke?

Are these cables placed near anything that might give off interference? Run across drop down ceilings that have flourescent light fixtures up there? Those ballasts wreak havoc with data cables, must keep cables far away from them.

[joshmac]

Thanks again YeOldeStonecat.

The problem might very well be those lights. The rooms have plenty of them. I'll see what i can do with them.

Thanks.