Really weird networking problem


G

Guest

I am trying to add 3 new PCs to a domain. The first is in an office where
there is already a client computer, so a new network jack was installed. When
I logged on, I got the "Network cable is unplugged" message. The light on the
back wasn't on. I asked maintenance to check the wiring. It checked out OK.
Tried to change settings on the card, but nothing worked, so we got a second
card. Same thing. I then tested the jack myself by plugging in another new
PC, same make and model, same onboard card. Same thing. No light, no
connection. I tried in the jack where a client computer has been working
fine for 2 years. No luck. Then I took an older standalone computer, and was
able to add it to the domain with no problem. I used the same cabling, the
same jack.

Took one of the problem PCs to another office where a new PC was due to be
installed, plugged in, connected to the LAN right away with no problems.

Took a 3rd new PC, different model and card. Plugged it into the network
jack in the problem office, the light was green. Thought we were good to go.
As soon as I booted up the computer, the light went off, the "Network cable
unplugged " message was displayed, and I couldn't get anywhere.

This seems to suggest a software problem. The only other factor I see is
that all 3 network cards that won't work are bootable, and the boot sequence
has them 3rd. However, if this is the issue, I don't see why the very same
PCs would work in other locations in the building.

If anyone has any sugegstions, I would be very grateful.
 
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C

Chuck [MVP]

I am trying to add 3 new PCs to a domain. The first is in an office where
there is already a client computer, so a new network jack was installed. When
I logged on, I got the "Network cable is unplugged" message. The light on the
back wasn't on. I asked maintenance to check the wiring. It checked out OK.
Tried to change settings on the card, but nothing worked, so we got a second
card. Same thing. I then tested the jack myself by plugging in another new
PC, same make and model, same onboard card. Same thing. No light, no
connection. I tried in the jack where a client computer has been working
fine for 2 years. No luck. Then I took an older standalone computer, and was
able to add it to the domain with no problem. I used the same cabling, the
same jack.

Took one of the problem PCs to another office where a new PC was due to be
installed, plugged in, connected to the LAN right away with no problems.

Took a 3rd new PC, different model and card. Plugged it into the network
jack in the problem office, the light was green. Thought we were good to go.
As soon as I booted up the computer, the light went off, the "Network cable
unplugged " message was displayed, and I couldn't get anywhere.

This seems to suggest a software problem. The only other factor I see is
that all 3 network cards that won't work are bootable, and the boot sequence
has them 3rd. However, if this is the issue, I don't see why the very same
PCs would work in other locations in the building.

If anyone has any sugegstions, I would be very grateful.

What's at the other end of the cable in the problem office? Try another port on
it.

This sounds like Auto-MDIX / duplexing acting up. When AUto-MDIX first came
out, this sort of crap would happen with certain NICs, unless the ports were
setup a certain way. It's a combination of Auto-MDIX on the switch and the NIC,
or the duplex setting on the two.

--
Cheers,
Chuck, MS-MVP 2005-2007 [Windows - Networking]
http://nitecruzr.blogspot.com/
Paranoia is not a problem, when it's a normal response from experience.
My email is AT DOT
actual address pchuck mvps org.
 
G

Guest

Chuck said:
I am trying to add 3 new PCs to a domain. The first is in an office where
there is already a client computer, so a new network jack was installed. When
I logged on, I got the "Network cable is unplugged" message. The light on the
back wasn't on. I asked maintenance to check the wiring. It checked out OK.
Tried to change settings on the card, but nothing worked, so we got a second
card. Same thing. I then tested the jack myself by plugging in another new
PC, same make and model, same onboard card. Same thing. No light, no
connection. I tried in the jack where a client computer has been working
fine for 2 years. No luck. Then I took an older standalone computer, and was
able to add it to the domain with no problem. I used the same cabling, the
same jack.

Took one of the problem PCs to another office where a new PC was due to be
installed, plugged in, connected to the LAN right away with no problems.

Took a 3rd new PC, different model and card. Plugged it into the network
jack in the problem office, the light was green. Thought we were good to go.
As soon as I booted up the computer, the light went off, the "Network cable
unplugged " message was displayed, and I couldn't get anywhere.

This seems to suggest a software problem. The only other factor I see is
that all 3 network cards that won't work are bootable, and the boot sequence
has them 3rd. However, if this is the issue, I don't see why the very same
PCs would work in other locations in the building.

If anyone has any sugegstions, I would be very grateful.

What's at the other end of the cable in the problem office? Try another port on
it.

This sounds like Auto-MDIX / duplexing acting up. When AUto-MDIX first came
out, this sort of crap would happen with certain NICs, unless the ports were
setup a certain way. It's a combination of Auto-MDIX on the switch and the NIC,
or the duplex setting on the two.

--
Cheers,
Chuck, MS-MVP 2005-2007 [Windows - Networking]
http://nitecruzr.blogspot.com/
Paranoia is not a problem, when it's a normal response from experience.
My email is AT DOT
actual address pchuck mvps org.

You were right on target. As it turns out, the pairs were reversed on the
cable and most of the NICs I tried did not compensate. Plugging in a
crossover cable confirmed the diagnosis. Thanks for your suggestion.
 
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C

Chuck [MVP]

Chuck said:
I am trying to add 3 new PCs to a domain. The first is in an office where
there is already a client computer, so a new network jack was installed. When
I logged on, I got the "Network cable is unplugged" message. The light on the
back wasn't on. I asked maintenance to check the wiring. It checked out OK.
Tried to change settings on the card, but nothing worked, so we got a second
card. Same thing. I then tested the jack myself by plugging in another new
PC, same make and model, same onboard card. Same thing. No light, no
connection. I tried in the jack where a client computer has been working
fine for 2 years. No luck. Then I took an older standalone computer, and was
able to add it to the domain with no problem. I used the same cabling, the
same jack.

Took one of the problem PCs to another office where a new PC was due to be
installed, plugged in, connected to the LAN right away with no problems.

Took a 3rd new PC, different model and card. Plugged it into the network
jack in the problem office, the light was green. Thought we were good to go.
As soon as I booted up the computer, the light went off, the "Network cable
unplugged " message was displayed, and I couldn't get anywhere.

This seems to suggest a software problem. The only other factor I see is
that all 3 network cards that won't work are bootable, and the boot sequence
has them 3rd. However, if this is the issue, I don't see why the very same
PCs would work in other locations in the building.

If anyone has any sugegstions, I would be very grateful.

What's at the other end of the cable in the problem office? Try another port on
it.

This sounds like Auto-MDIX / duplexing acting up. When AUto-MDIX first came
out, this sort of crap would happen with certain NICs, unless the ports were
setup a certain way. It's a combination of Auto-MDIX on the switch and the NIC,
or the duplex setting on the two.

--
Cheers,
Chuck, MS-MVP 2005-2007 [Windows - Networking]
http://nitecruzr.blogspot.com/
Paranoia is not a problem, when it's a normal response from experience.
My email is AT DOT
actual address pchuck mvps org.

You were right on target. As it turns out, the pairs were reversed on the
cable and most of the NICs I tried did not compensate. Plugging in a
crossover cable confirmed the diagnosis. Thanks for your suggestion.

Kewl. Thanks for the feedback.
<http://bloggerstatusforreal.blogspot.com/2006/09/peer-support-it-works-only-if-you-help.html>
http://bloggerstatusforreal.blogspot.com/2006/09/peer-support-it-works-only-if-you-help.html

--
Cheers,
Chuck, MS-MVP 2005-2007 [Windows - Networking]
http://nitecruzr.blogspot.com/
Paranoia is not a problem, when it's a normal response from experience.
My email is AT DOT
actual address pchuck mvps org.
 

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