Also affects ubuntu 11.10. Here's what was happening: my wifi interface was showing up as up but unmanaged (this is a very fresh installation, so that's how the installer left it), and 'route' showed
Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface default 192.168.0.1 0.0.0.0 UG 0 0 0 eth0 default 192.168.0.1 0.0.0.0 UG 100 0 0 wlan0 link-local * 255.255.0.0 U 1000 0 0 eth0 192.168.0.0 * 255.255.255.0 U 0 0 0 wlan0 192.168.0.0 * 255.255.255.0 U 1 0 0 eth0 The command 'ifconfig wlan0 down' fixed the problem! After that, the routing table was Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 192.168.0.1 0.0.0.0 UG 0 0 0 eth0 169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 eth0 192.168.0.0 0.0.0.0 255.255.255.0 U 1 0 0 eth0 and everything was hunky-dory. So the problem was that the installer left my system in an inconsistent state: wlan0 was up but not managed, and acted as a packet /dev/null 35 seconds out of every 43 seconds. ** Package changed: ubuntu => network-manager (Ubuntu) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/917399 Title: Ubuntu 12.04 alpha 1 network flaky after update To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/917399/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs