Cohabitation problem between the cisco_ucsm mechanism driver and an l3 router through an ovsvlan network.

Issue

• We proceeded to the FFU OSP10 -> OSP13 without the ucsm mechanism driver. We have a router L3 accessible through an ovsvlan for a VM which work perfectly.

• We then add the ucsm mechanism driver configuration and proceeded an update of the stack. We have then this situation:

• When the UCSM mechanism driver is configured in the ml2_conf.ini file (mechanism_driver = openvswitch, cisco_ucsm), the external gateway of the qrouter L3 is no longer accessible (ping).

• When we remove the mechanism driver in the ml2_conf.ini file (mechanism_driver = openvswitch), the external gateway of the qrouter L3 becomes accessible again (ping).

• We need that external access through an L3 router remains available with the Mechanism driver activated.

• If we wait long enough, The L3 qrouter will eventually start pinging.