Fresh install on Asus P7T deluxe. Which has twin NIC's onboard. Both cards have cables attached to a switch with IP's from DHCP and a valid route to the internet.

Internet connectivity fails until either of the network cards is disabled.

Network manager should either disable one of the cards, bond the connection or route using a single connection until such point as that connection is disconnected and then fall back to the other.

Any idea why this fails ?

Regards Simon

Update: Bug logged. https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1018740

  • Sounds like a bug report. Anyway, there are lots of information that is missing for anyone to be able to help you. Add to you question the output of commands 'ip address' and 'ip route' when you net works and doesn't work.
    – Anders
    Jun 14, 2012 at 22:18

2 Answers 2


I've also noticed an issue with this, and it appears to be udev related. Basically, udev reassigns one of the NIC's logical names, for no apparent reason. On top of this, it appears to be messing up the MAC addresses when the dirver is actually loaded, after the logical name of the device has been changed. Time for a bug report me thinks.


This seems to be working if Ubuntu is up to date as of September. Must have been fixed with a patch, it's certainly not occurring any more.

Not the answer you're looking for? Browse other questions tagged .