I recently created a VXLAN test setup with single-NIC compute nodes
(using OpenStack Juno on Fedora 20), conciously ignoring the OpenStack
advice of using nodes with at least 2 NICs ;-) .
The fact that both native and encapsulated traffic needs to pass through
the same NIC does create some interesting challenges, but finally I got
it working cleanly, staying clear of MTU pitfalls ...
I documented my findings here:
For those interested in single-NIC setups, I'm curious what you think
about  (a small patch is needed to add "VLAN awareness" to the
qg-XXX Neutron gateway ports).
While catching up with Neutron changes for OpenStack Kilo, I came across
the in-progress work on "MTU selection and advertisement":
 Patch review: https://review.openstack.org/#/c/153733/
 Spec update: https://review.openstack.org/#/c/159146/
Seems like  eliminates some additional MTU pitfalls that are not
addressed by [3-5].
But I think it would be nice if we could achieve  while coordinating
with the "MTU selection and advertisement" work [3-5].
Fredy ("Freddie") Neeser
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