STRANGE NETWORK PROBLEM

[Stratos Laspas]

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Something strange is going on.

I have an adsl connection. I have a zyxel 653 modem/router/dhcp server
connected to the line. The PC is running dapper and it is connected to
the router via the eth0 connection.

Problem:
After a few minutes of connection (period varies), I can no longer
connect to the internet.

More data on the problem:
1) I have squid as caching proxy. When the problem occurs, I restart
squid with no effect.
2) These services do not work: browsing, connection to external pop
server, updating through synaptic or adept
3) This works: ping
4) Tried rebooting the router, no effect
5) I see activity on the router (possibly my pc asking for data)
6) I use firestarter as firewall
7) If I go to the network settings, the eth0 connection appears enabled
8) If I go to the network settings and then first disable the eth0
connection, then re-enable it, the network connection comes back up, but
fails again after a while
9) I have noticed that if I press the "get mail" button on thunderbird,
the network comes down sooner (after about minute), every time

Any hints?

Thanks,
Stratos
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