Network intermittently goes down constantly!

[Aaron]

I'm having the following strange networking problem on win2k:

Periodically I lose partial network connectivity beyond my LAN. I can
always ping any box on my LAN (on 192.168.x.x) and my gateway... however
several times an hour I lose connectivity outside my LAN, and that downtime
is 20-30% of the total time!

when the network is up, I can ping an external host (like yahoo.com) and I
see the activity light on my network card indicating that the packets were
sent.

However when the network goes down, when I try to ping an external host, I
see the message "request timed out" and NO activity light blinks, meaning
the packets weren't even sent! However I can still successfully ping any
box on my network and see the activity light blink!

Also strange, is that SOMETIMES I can get the network working again by
opening another cmd window and trying to telnet to another host, and hitting
the enter key (but this doesnt always work)

How can I troubleshoot this?

 

[Frankster]

I'd look to the router and check its up/down times. Maybe it is retraining
frequently due to a bad config or a bad phone line.

Could be DNS issues I guess, but, "request timed out" really means that you
didn't receive a reply, not that your request was not sent. If you have
local/external DNS issues, you would probably have received a "could not
find host" type message.

-Frank

 

[Aaron]

It's not a DNS issue because when it happens I can't ping any external sites
using the numeric ip address.

And it has nothing to do with the router, because it happens at work and a
friends house too.

Its a software issue, maybe a configuration conflict of some type.

Help, anybody?