If this problem is related to this one - https://bugs.launchpad.net/ubuntu/+source/qemu- kvm/+bug/1325560?comments=all - then upgrading the kernel should fix it.
In my case I'm using Ubuntu 14.04 with kernel 3.13 and after upgrading to kernel 3.16, no more connectivity problems. -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to qemu-kvm in Ubuntu. https://bugs.launchpad.net/bugs/997978 Title: KVM images lose connectivity with bridged network To manage notifications about this bug go to: https://bugs.launchpad.net/nova/+bug/997978/+subscriptions -- Ubuntu-server-bugs mailing list [email protected] Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
