A Network Cable is Unplugged - Solution

[Computer_Engineer]

Hello Everyone,

My internet was working fine, when I surfed some websites which
infected my Computer (running Windows XP Home) with Backdoor.Lixy
virus and 13 other adware viruses. My internet connection stopped
working after restarting. I tried to get rid of the virus with Norton
Antivirus 2003 and also with AVG Antivirus, but of no avail. Both
virus scanners detected the virus but were unable to delete it. Then
formatting the C drive got rid of the virus.

I did a lot of searching in the internet and found that this error
message "A network cable is unplugged" is pretty common among winxp
users. But I did not find the reason for this error message, which has
prompted me to write to the newsgroup so that others spend less time
on this problem.

In fact the virus was using my computer (with a dedicated ip address
assigned from an University Resnet service) as a server. The resnet
detected this activity and blocked my MAC address from the network. I
called them up and then they again enabled internet access. So I guess
if your internet works fine and stops suddenly saying " a network
cable has been unplugged", its more likely because your isp is
blocking access, rather than a bad jack. Contact your isp to resolve
this problem.

Hope this helps,
Computer_Engineer

 

[Dave In San Pedro]

I'm having a similar problem, though it is intermittent.

Configuration: Pentium III 600Mhz, 384MB RAM, WindowsXP Pro, IE 6, Belkin
F5D7230-4 Wireless/Cable Gateway Router, and DSL. This machine is plugged
into (via cable) the router. There is a laptop that operates on the
wireless side that does not have this problem. These machines and network
were operating flawlessly since installation of the network which was about
3 months before the problem appeared.

With no obvious reason, my "LAN Connection 3" issues a "A network cable is
unplugged" error. Outlook and IE no longer have online access when this
happens. The error message is then replaced by another message "LAN
Connection 3 100 Mbps" at which point everything usually resumes working as
though nothing had happened.

I say "usually" because sometimes the behavior is such that it rapidly
bounces back and forth between the two messages above and there is no time
for anything to re-establish connectivity with internet sites.

There is a workaround that sometimes corrects the problem. I go to "LAN
Connection 3" Properties - Configure - Advanced - LinkSpeed/Duplex Mode and
select "10 Half Mode". Sometimes this requires a reboot of the system to
take effect. Sometimes a reboot of the system itself will correct the
problem. However, both "fixes" are temporary and last anywhere from a few
minutes to several days.

Sometimes it seems that the problem can be induced. If it's been working
fine for a day or so in "10 Half Mode" and I go back and set it to "Auto
Mode", the problem will immediately appear. When set to "Auto Mode" it
usually tries to go to 100 Mbps and I do not know if the higher speed is the
problem or something else.

When in the "A network cable is unplugged" state, if a "Repair" (rightclick
the network icon and leftclick "Repair") is attempted, it will pause for
some time then come back with an error message with words to the efffect
that it was unable to obtain an IP address and to contact the LAN
administrator.

What seems so strange to me is that the laptop on the wireless connection is
completely oblivious to this. I've replaced the "cable" in question.
Fooling with the cable layout between the PC, router, and modem
kinda-sorta-appears-maybe to have some effect.

Could there be crosstalk between the PC-to-router cable and the
router-to-moderm cable?

This is not a show stopper. If I have to I can revert back to dial-up to
get mail. But the lady of the house has no patience for this kind of
nonsense and when she's not happy... well...

Any ideas? Anyone?

Thanks,

Dave M.

 

[Jetro]

Is the computer plugged directly into Resnet network?

 

[Dave In San Pedro]

I don't know. The computer is plugged into 1 of the 4 jacks available on
the back of the router. There is an "ethernet adaptor" internal to the
computer which presents a female jack at the back of the PC that the other
end of this cable plugs into.

Regards,

Dave M.

 

[Jetro]

Sorry, Dave, I asked the OP.
Create HKLM\SYSTEM\CCS\Services\Tcpip\Parameters, REG_DWORD
DisableDHCPMediaSense, data 1.

 

[Kent W. England [MVP]]

I did a lot of searching in the internet and found that this error
message "A network cable is unplugged" is pretty common among winxp
users. But I did not find the reason for this error message, which has
prompted me to write to the newsgroup so that others spend less time
on this problem.

... So I guess
if your internet works fine and stops suddenly saying " a network
cable has been unplugged", its more likely because your isp is
blocking access, rather than a bad jack. Contact your isp to resolve
this problem.

The only thing that causes this error message is to have the cable
physically disconnected from the other computer or the hub/switch. This
is a common error message on two-computer cross-over cable connections
and home phoneline networking networks. If the hub port is disabled and
powered off, this could also cause that error message. But that is a bit
more than simply blocking your MAC address. Cable and DSL Internet
services are provided by the cable or DSL modem. Even if your cable or
DSL service is not working, it is likely that the modem port is powered
up, so you won't see that error message.

Try it yourself. Plug your port into an Ethernet hub, switch, or cable
modem and then unplug it. See the balloon. Plug in the switch power.
Balloon gone.