Interesting problems with Ethernet Card of XPS 1640

My XPS studio 1640 has a problem with the connection via ethernet card. It is always disconnected after exactly every 30 minutes and connected in few seconds after that. I've scaned viruses but not any virus is found, I've set-up new Windows but still got problem. Anyone has same case . help me plz, I can't play Starcraft 2 with this frequently disconnected connection (

 

Interesting. I have the same problem. My laptop is approx 1.5 years old and I never attempted to use ethernet port until recently. I've spent last 3 weeks troubleshooting the problem (different drivers, etc...). However, same issue when I boot directly into Ubunutu. I'm starting to believe it is an issue with on board LAN. I don't think these laptop has separate mini-PCI card (at least I couldn't find it when I opened my laptop). I'm still under warranty and will be contacting Dell shortly

 

Finally tracked the issue to DLINK 1G 8 port switch. I have a second 4 port 1G switch. I placed two computers on that switch and nothing else. Manually assigned IP addresses and ran several tests using ttcp or NTttcp tool. Ran perfectly, got it as high as 90% bandwidth utilization.

 

It might be possible that the DHCP IP lease is timing out, have you checked to see how long your IP lease times are via "ipconfig /all" ? Does your IP stay the same after the disconnects/etc? How are you connected, cable modem/DSL, directly/switch/router, other special network configuration? Tried bypassing router/switch if you have one and directly connecting to the modem? How does it perform with other hardware (router/modem) and at other locations? It could be your network configuration or some other part of it like the last poster found.