Rogue network cable Can't connect using switch

[krsnendu]

Hi,
I have an underground cable connecting a classroom to the main server.

If I plug any computer directly into the underground cable it connects to the server fine.

If I plug a switch into the cable, none of the computers connected to the switch gets an IP address from the server. When I try to assign manual IP addresses I also can't connect.

But when I use the same switch and plug it into the server using a shorter cable everything works.

What could be the problem? Could it be a cross over vs straight through wiring problem? Any other suggestions?

 

[Emerald]

what kind of switch is it that you are using?

 

[krsnendu]

Just a regular 8 port switch with uplink. I have tried using uplink. It made no difference. I also tried using a 4 port switch with wireless.

I have a feeling there is something round with the cable. Good enough to work directly to a computer but not through a switch.

I used a cable tester and got these results:
Lights the lit up.
Sending unit
123456 8
Receiving unit
12 8 3 654

 

[Emerald]

it is the wire that is wrong.

for cross over it should show:
12345678 T568B
36145278 T568A

for the regular it should show:
12345678 T568B
12345678 T568B

http://en.wikipedia.org/wiki/TIA/EIA-568-B

 

[krsnendu]

Thanks. I'll try to change the plugs.

Strange that the computer plugged in directly can handle it but not the switch.

 

[krsnendu]

Best answer selected by krsnendu.