Hello world 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: [1] http://blog.systemathic.ch/2015/03/06/openstack-vxlan-with-single-nic-compute-nodes/ [2] http://blog.systemathic.ch/2015/03/05/openstack-mtu-pitfalls-with-tunnels/ For those interested in single-NIC setups, I'm curious what you think about [1] (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": [3] Spec: https://github.com/openstack/neutron-specs/blob/master/specs/kilo/mtu-selection-and-advertisement.rst [4] Patch review: https://review.openstack.org/#/c/153733/ [5] Spec update: https://review.openstack.org/#/c/159146/ Seems like [1] eliminates some additional MTU pitfalls that are not addressed by [3-5]. But I think it would be nice if we could achieve [1] while coordinating with the "MTU selection and advertisement" work [3-5]. Thoughts? Cheers, - Fredy Fredy ("Freddie") Neeser http://blog.systeMathic.ch