Home network problem.. internet connection goes down frequently

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I have a lan set up at home using a Netgear WGR614 router. I have three
computers connected to it. My problem is that one of the computers
which is kept at quite a distance from the router (uses a 15 metre long
cable) keeps loosing internet connection quite frequently. Its like the
network just goes to some sort of 'sleep' condition.

So i have to put in a lot of trial and error effort to gain access to
the internet again - i first do a
ping just to see if i am getting a reply from the router. This is okay
most of the times. Then i have to disable / enable /repair my ethernet
connection many times to make the internet  working somehow.

Also the place where i have connected my cable it does not blink at the
frequency at which the others connections are blinking (or sometimes it
just glows green)

Any ideas where could the problem be? Is the length of the cable
causing a problem? Are there any ways to ascertain the cause of the

My system config :
Runs WinXp / Ubuntu Linux (problem with both the OS).
Onboard VIA ethernet adapter & a realtek adapter in PCI slot (Problem
with both of them).
A7V400MX, AMD Athlon XP 2400+, 256MB DDR RAM.


Re: Home network problem.. internet connection goes down frequently

Alanz wrote:
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Is the cable pre-manufactured, or did you cut it yourself?  Can you get
a replacement cable to see if that improves the situation?

Re: Home network problem.. internet connection goes down frequently

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Your cable length should be OK.


The ethernet cable has no shielding, and relies on differential
transmission. The idea is, a noise signal, couples to both wires
to the same amount. The devices at the end of the cable, "subtract"
the signals from one another, and the noise component cancels out.

If an electrical noise source is so extreme, that the coupling
to each wire is slightly different (because no wire is perfect),
that noise could upset the Ethernet signal. For example, if you
were running a Tesla coil, or a door bell buzzer (one that throws
sparks from the contacts inside the buzzer), right next to
the cable, the signal might not get through unaltered.

One way to characterize wires, is with TDR (time domain reflectometry).
That is an electrical technique, where a signal is sent down the
line, and the test equipment analyses the returned reflections
in the cable. For example, if the contacts on the connectors are
not making good contact, then the transmission characteristics will
be far from ideal.

Some of the Marvell ethernet chips, come with an application called
VCT or virtual cable tester. That software uses a feature inside
the Ethernet chip, where the Ethernet chip functions as a piece of
test equipment. A cable connected to a Marvell ethernet chip, can
be tested for opens, shorts, or "just the right impedance". Some
motherboards have such Ethernet chips right on the motherboard,
and if you own a motherboard like that, you can connect that
computer to the end of the cable and test the cable.

Some operating systems keep track of transmission statistics.
If there are a lot of "CRC errors", then that would suggest
a wiring problem. If you know of some way to access the
statistics collected by your Ethernet controller, that might
give you some idea as to how much trouble the Ethernet chip
is having with your physical plant (wiring). Compare the
statistics from all three computers, so you'll get some idea
of what is "normal".


Re: Home network problem.. internet connection goes down frequently

On 5 Jun 2006 10:26:01 -0700, "Alanz"

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Look in Event Viewer to see if anything is seemingly related
to networking.  

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"Most" of the time?  You should always get a ping through,
if that fails then ping that system from itself.  Wiggle the
cable and wait a minute and retry it.  Temporarily move the
one system closer and try swapping in a different cable.  15
meter is not a problem, that's a relatively short cable.

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Is it an old system?  Maybe dust or residue accumulation in
the port socket?  Try another port on the router too, it's
possible to blow out a port from a power surge though that
tends to completely kill the port, not intermittently
working still.  Even so, try another port and cable and try
a properly working system on that port and cable... reduce
the variables.

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Do you use both of the NICs?  Try disabling one, actually
try uninstalling both then only installing one.

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