Hi, Due to network related API changes between the enging and VDSM, cluster 3.1 host agents should be updated: Starting from ovirt-engine commit ec5f528e80ac8e7b2d8bb4f65eb46391233fd1fd, VDSM must include commit 1fa30a08b93c5ba76c8f5377d030d8a597023d18. The expected behaviour without an updated VDSM, is having all 3.1 hosts as non-operational due to missing networks. Regards, Moti