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

Solution In Progress - Updated -


  • 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.


  • Red Hat OpenStack Platform 13.0 (RHOSP)

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