Openvswitch setup with Mitaka, unable to ping interfaces.

With a new Mitaka setup we encounter a problem in relation to Openvswitch.

The setup is as following for the "OVS Classic" setup (refer to doc "Networking"):

• Set of hosts (Ubuntu 14.04LTS) on same LAN with each main bond interface with 3 VLANs for the target architecture;
• KVM VMs for Controller, Network and Compute nodes (Ubuntu 16.04LTS) over bridges on top of VLANs, networking works fine, VMs can ping hosts.
• In Network node whilst configuring the OVS bridge, for example with the vs br-tun bridge we are unable to ping hosts. This is done after removing the IP address form the VS port and allocating it to the vs bridge. tcpdump seems to indicate a layer 2 problem. Although this seems to be a common problem with OVS bridges, after Googling around we can't figure out what is wrong.

Below an excerpt of /etc/network/interfaces for the related bridge and port.

auto eth2
iface eth2 inet manual
up ifconfig $IFACE 0.0.0.0 up up ip link set$IFACE promisc on
down ip link set $IFACE promisc off down ifconfig$IFACE down

auto br-tun
iface br-tun inet static