Ubuntu 10.10 Network Disconnecting

[The Swamp]

So, I got a nasty virus last weekend on my Win7 machine. Not sure what it was or how I even got it. For some reason MS Security Essentials didn't stop it, even with the latest updates installed. It was a worm that hid my boot sector and gave me a Black Screen of Death. Then it downloaded some kind of crazy fake virus checker that I was not able to get rid of even in safe mode with Combofix.

Luckily, I had a pretty fresh disk image on another spare drive in the closet, so I was able to do a low level format and reinstall the image on the affected drive. I decided to install Wubi on a spare partition and I use that now for surfing the net and email. I don't want to have to deal with another crazy virus attack. So far, it seems to be working okay. But I am having an issue that I have seen before with an earlier Ubuntu install.

After a few hours, the OS reports that the wired internet connection is disconnected. I have no idea what is causing this. I noticed with the other Ubuntu install the same thing. I was just rebooting the system to get internet and network connectivity back, but I discovered that I can reset the Network Connections setting and get the connection back. So I no longer have to do a full reboot.

The question is what is going on here? Any ideas on what causes the network connection to "time out" or so it seems? It happens whether or not I am using a live connection. It just did it a few moments ago.

JBI? Are you around...? Help!

[flip-mode]

Are you on a static network or DHCP?

What is the router / modem you are connecting to? Have you tried rebooting that?

Are you using network manager or configuring through /etc/network/interfaces ? I've always had bad experiences with the network manager and stopped using it a while back and just use /etc/network/interfaces

[notfred]

10.10's Network Manager seems to be solid on my work laptop where I switch back and forth between wired when docked and wireless in meeting rooms. I wonder if the DHCP server on your router has some nasty bug where it hands out a lease for a short period and then refuses to renew it for a longer period or something similarly bizarre. I would check for a firmware upgrade for the router.

[The Swamp]

I'm on a dynamic DHCP. But, the thing is I don't have this problem with Windows. It seems if there was some problem with the router, it would appear in any OS. It's only the Ubuntu distros that drop the connectivity.

[cheesyking]

if you've got a spare partition then try it without wubi.

Does anything show up in messages or syslog?

Check either with the cli:
open 2 terminals and leave these commands running, one in each. See what appears when you loose the network.
tail -f /var/log/syslog
tail -f /var/log/messages
press "ctrl c" to stop them running

or the gui:
System => Administration => Log File Viewer

[notfred]

It seems if there was some problem with the router, it would appear in any OS. It's only the Ubuntu distros that drop the connectivity.

Every manufacturer tests against a Windows PC. They can be sending complete garbage but as long as the Windows PC works, they'll ship it. You could installing wireshark and capturing the DHCP exchange (force the link down and up to get it to re-DHCP) and see if it looks good or bad.

[just brew it!]

Sorry for being late to this thread, this weekend has been a bit crazy.

I've not seen the specific behavior you describe, though I have seen occasional Network Manager weirdnesses in Ubuntu going all the way back to 8.10 or 9.04. Network Manager seems to have gotten a lot better, but it is still not perfect; IMO if you are using a wired connection only, you may be better off uninstalling Network Manager entirely and configuring the interface manually via the /etc/network/interfaces file.

If you'd like to pursue this, we can walk you through it... it's not rocket science, but does involve manual editing of configuration files.