Have you checked to see weather the NetworkManager process is still running when this occurs, and if it is not, try plugging the cable back in and restarting NetworkManager. Also check /var/log/syslog.
I am seeing an issue where if I boot my 12.04.1 server with the cable unplugged, NetworkManager dies (it must be repeatedly crashing, because I think upstart tries to restart it). Also, if I unplug the cable while the server is up and then use nmcli to try to start a 3g modem interface, NetworkManager sometimes dies. In both cases, if I plug the cable back in, I can restart NetworkManager. I can see that there's alot going on here, and I do run scripts that shutdown the interfaces when I update iptables lists, so I'm not sure I can easily provide instructions on how to reproduce this. It may be related to the RealTek 9139 driver. My hardware is a tiny box with a VIA EDEN chip and RealTek RTL8139 interfaces. I am in the process of moving, so can't spend alot of time debugging this right now, but will try to provide further information in the coming weeks. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1053022 Title: Ubuntu 12.04 crashes if lan cable is pulled out from emachines laptop To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1053022/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
