Comment 4 for bug 1482166

After investigation of vCenter settings I discovered the root cause.

In vCenter there was two port groups both named 'br100'. One was
connected to standard vSwitch (br100 - standard switch network),
second one was connected to distributed vSwitch (br100 - distributed port group).

In nova-network configuration we specify flat_network_bridge which, when vCenter
is used, means that nova-compute (not nova-network!) will provision network port
on this port group.

During VM creation VM ports were provisioned on standard network 'br100' that was
not assigned correct VLAN tag (103).

After removing standard switch network 'br100' VMs were able to get
IP address and connect to to external networks.

Marking as Invalid since this is pure infrastructure problem.