Several times a day lost network in the guest Windows Server 2008.
In the logs:
Feb 6 13:07:22 cluster-2 kernel: vmbr0: port 4(tap114i0) entering disabled state
Feb 6 13:07:22 cluster-2 kernel: vmbr0: port 4(tap114i0) entering disabled state
pveversion
pve-manager/2.2/3089a616...