Quagga peering doesn't seem to work over the NATted openstack external
network. To work around this, directly patch the quagga instance to the
external network and give it a fixed IP in that network. Then, all the
peering traffic goes over that patched interface.
Change-Id: I8d9d8fef4e86839c821f83e564d5c49cc15e43ae
JIRA: SDNVPN-114 Signed-off-by: Romanos Skiadas <rski@intracom-telecom.com>