Description of problem: Open vSwitch forbids to raise MTU for devices that are in the same namespace with the bridge, but allows that same operation once the device in question is moved into another namespace. This is a side effect of missing validation in vswitchd implementation for plugged interfaces located in other namespaces. This effectively lowers MTU for router interfaces from what is supported by underlying physical interfaces. With that, frames from an external network of infrastructure MTU size will not be served by affected routers. Expected results: The fix reverses the order of interface plugging procedure steps, first moving ports into namespaces, then setting their MTUs. This seems to solve the issue.
*** Bug 1348115 has been marked as a duplicate of this bug. ***
Code tested on latest puddle, openstack-neutron-8.1.2-3.el7ost
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://rhn.redhat.com/errata/RHBA-2016-1759.html