Windows XP: 100 mbit connection gives no connectivity; 10 mbit ok

P

Paul

The following problem has had me stumped for the past few days. I have
two Windows XP SP2 machines hooked up to a 10/100 mbit router to the
internet. The machine I'm writing this from is hooked up just fine with
a 100 mbit connection.

The other machine, however, has some problems. The on-board 10/100 mbit
NIC has worked previously, but no longer works since I reinstalled the
computer for my father. I have a completely new installation of Windows
-- as fresh as you can imagine -- but the network would not work. I
first tried acquiring an IP address automatically, which, after about 5
long minutes of acquiring, returned the following:

IP: 169.254.158.74
Gateway: 255.255.0.0

This seems to be in the domain of the standard settings if Windows uses
when it can't reach the DHCP server. But as we know, the server is
working fine since I'm using it as I type this message. I believe that
connecting to the DHCP fails for some reason, perhaps because of the
line speed (?).

The router is set up such that it *should* be:

Gateway (router's IP): 10.0.0.2
Subnet mask: 255.0.0.0
DNS (router's IP): 10.0.0.2

Just to be sure, I checked the status of the LAN here, and these are
indeed the settings we should be using.

Using the incorrectly appointed IP address above of course results in
XP telling me I have 'limited or no connectivity', I can only send
packets while no packets are received, and the network connection does
zilch, i.e.: the computer cannot be seen nor can it see others.

If I configure the network manually, using the proper settings, a
network connection is made and Windows says everything is hunky-dory.
However, once again, no packets are received from the router and the
network connection still does zilch; Windows just doesn't know it.

To my surprise, if I *only* change the line speed from 100 mbits to 10
mbits (either full or half, neither makes a difference) everything
works like a charm, even getting an IP via DHCP.

I've also tested the cable using a laptop; 100 mbits full-duplex works
perfectly fine.

The NIC device used uses the Realtek RTL8139/810x Family Fast Ethernet
chipset with driver version 5.649.615.2006 (most recent as of this
message). It may be worth mentioning that I've tried resetting WinSock
2 (which wouldn't have been necessary anyway, since I just reinstalled
XP) and IPv6 is *not* installed.
 
S

Steve Winograd [MVP]

The following problem has had me stumped for the past few days. I have
two Windows XP SP2 machines hooked up to a 10/100 mbit router to the
internet. The machine I'm writing this from is hooked up just fine with
a 100 mbit connection.

The other machine, however, has some problems. The on-board 10/100 mbit
NIC has worked previously, but no longer works since I reinstalled the
computer for my father. I have a completely new installation of Windows
-- as fresh as you can imagine -- but the network would not work. I
first tried acquiring an IP address automatically, which, after about 5
long minutes of acquiring, returned the following:

IP: 169.254.158.74
Gateway: 255.255.0.0

This seems to be in the domain of the standard settings if Windows uses
when it can't reach the DHCP server. But as we know, the server is
working fine since I'm using it as I type this message. I believe that
connecting to the DHCP fails for some reason, perhaps because of the
line speed (?).

The router is set up such that it *should* be:

Gateway (router's IP): 10.0.0.2
Subnet mask: 255.0.0.0
DNS (router's IP): 10.0.0.2

Just to be sure, I checked the status of the LAN here, and these are
indeed the settings we should be using.

Using the incorrectly appointed IP address above of course results in
XP telling me I have 'limited or no connectivity', I can only send
packets while no packets are received, and the network connection does
zilch, i.e.: the computer cannot be seen nor can it see others.

If I configure the network manually, using the proper settings, a
network connection is made and Windows says everything is hunky-dory.
However, once again, no packets are received from the router and the
network connection still does zilch; Windows just doesn't know it.

To my surprise, if I *only* change the line speed from 100 mbits to 10
mbits (either full or half, neither makes a difference) everything
works like a charm, even getting an IP via DHCP.

I've also tested the cable using a laptop; 100 mbits full-duplex works
perfectly fine.

The NIC device used uses the Realtek RTL8139/810x Family Fast Ethernet
chipset with driver version 5.649.615.2006 (most recent as of this
message). It may be worth mentioning that I've tried resetting WinSock
2 (which wouldn't have been necessary anyway, since I just reinstalled
XP) and IPv6 is *not* installed.

You've done some good troubleshooting to isolate the problem, Paul.

Connecting successfully at 10 mbit but not at 100 mbit usually means
that something in the network hardware is substandard. An improperly
wired cable is the most common problem that I've seen.

If the same cable and router port work OK with another computer, that
points to the Realtek NIC as the likely culprit. Try connecting that
NIC using a different cable and different router port.

If nothing else works, consider installing a second network adapter.
--
Best Wishes,
Steve Winograd, MS-MVP (Windows Networking)

Please post any reply as a follow-up message in the news group
for everyone to see. I'm sorry, but I don't answer questions
addressed directly to me in E-mail or news groups.

Microsoft Most Valuable Professional Program
http://mvp.support.microsoft.com
 
P

Paul

Thanks for the hasty reply, you two!

I have indeed briefly tried using another NIC, but had some
difficulties removing the drivers for the old one and didn't have
enough time to really test it well. First impression was that the
behavior was very similar if not the same.

This leads me to believe that the network cable is indeed damaged. I'm
still puzzled as to why 100 mbits worked using my notebook. I will try
placing the router next to the PC and hooking up a working cable to it
directly.

I will be sure to post the results.


Regards,
Paul
 

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