Thanks indeed, I'm with Nicolas, also working on a nice setup with this information!
Here is some more logging:
The error came after I added WAN_02_02 with no IP.
2013-02-13 10:55:00,455 INFO [org.ovirt.engine.core.dal.dbbroker.auditloghandling.AuditLogDirector] (QuartzScheduler_Worker-9) [41071339] No string for VDS_ACTIVATE_ASYNC type. Use default Log
2013-02-13 10:55:00,456 INFO [org.ovirt.engine.core.bll.AutoRecoveryManager] (QuartzScheduler_Worker-9) [41071339] Autorecovering 0 storage domains
2013-02-13 10:59:05,376 INFO [org.ovirt.engine.core.bll.LoginAdminUserCommand] (ajp--127.0.0.1-8702-10) Running command: LoginAdminUserCommand internal: false.
2013-02-13 10:59:06,266 ERROR [org.ovirt.engine.core.utils.ServletUtils] (ajp--127.0.0.1-8702-5) Can't read file "/usr/share/ovirt-engine/docs/DocumentationPath.csv" for request "/docs/DocumentationPath.csv", will send a 404 error response.
2013-02-13 10:59:43,948 INFO [org.ovirt.engine.core.bll.network.host.SetupNetworksCommand] (ajp--127.0.0.1-8702-19) [683f2e62] Running command: SetupNetworksCommand internal: false. Entities affected : ID: 033febb8-4f52-4253-bb6d-a8807816affd Type: VDS
2013-02-13 10:59:43,951 INFO [org.ovirt.engine.core.vdsbroker.vdsbroker.SetupNetworksVDSCommand] (ajp--127.0.0.1-8702-19) [683f2e62] START, SetupNetworksVDSCommand(HostName = KVM-02, HostId = 033febb8-4f52-4253-bb6d-a8807816affd, force=false, checkConnectivity=true, conectivityTimeout=120,
networks=[WAN_02_02 {id=6f38699a-3dea-4a96-987e-035e4041afdf, description=null, subnet=null, gateway=null, type=null, vlanId=null, stp=false, dataCenterId=56272dcf-0a66-489d-9a1e-4a1965207b64, mtu=0, vmNetwork=false, cluster=NetworkCluster {id={clusterId=null, networkId=null}, status=OPERATIONAL, display=false, required=true}}],
bonds=[],
interfaces=[eth3 {id=3b31007b-a0f5-472b-8906-9170ea00be96, vdsId=033febb8-4f52-4253-bb6d-a8807816affd, name=eth3, macAddress=00:1c:c4:d8:cb:34, networkName=officevms, bondName=null, bootProtocol=STATIC_IP, address=172.16.20.0, subnet=255.255.255.0, gateway=null, mtu=1500, bridged=true, speed=1000, type=0, networkImplementationDetails={inSync=true, managed=true}},
eth1 {id=4760e6c8-73d0-41c3-9a39-1ebc48e08879, vdsId=033febb8-4f52-4253-bb6d-a8807816affd, name=eth1, macAddress=00:1f:29:5a:5a:b5, networkName=vmstorage, bondName=null, bootProtocol=STATIC_IP, address=172.16.12.20, subnet=255.255.255.0, gateway=null, mtu=1500, bridged=true, speed=1000, type=0, networkImplementationDetails={inSync=true, managed=true}},
eth2 {id=713f2687-6d84-4010-9076-fbfc67cf6831, vdsId=033febb8-4f52-4253-bb6d-a8807816affd, name=eth2, macAddress=00:1c:c4:d8:cb:36, networkName=WAN_02_02, bondName=null, bootProtocol=NONE, address=, subnet=, gateway=null, mtu=0, bridged=false, speed=1000, type=0, networkImplementationDetails=null},
eth0 {id=1d3c9fef-8f9f-4f32-96c0-11c39f6c2e89, vdsId=033febb8-4f52-4253-bb6d-a8807816affd, name=eth0, macAddress=00:1f:29:5a:5a:b4, networkName=ovirtmgmt, bondName=null, bootProtocol=STATIC_IP, address=172.16.8.20, subnet=255.255.255.0, gateway=172.16.8.254, mtu=1500, bridged=true, speed=1000, type=2, networkImplementationDetails={inSync=true, managed=true}}],
removedNetworks=[],
removedBonds=[]), log id: 1ff9ba0e
2013-02-13 10:59:43,960 INFO [org.ovirt.engine.core.vdsbroker.vdsbroker.SetupNetworksVDSCommand] (ajp--127.0.0.1-8702-19) [683f2e62] FINISH, SetupNetworksVDSCommand, log id: 1ff9ba0e
2013-02-13 10:59:44,975 ERROR [org.ovirt.engine.core.vdsbroker.vdsbroker.BrokerCommandBase] (ajp--127.0.0.1-8702-19) [683f2e62] org.ovirt.engine.core.vdsbroker.vdsbroker.VDSNetworkException: VDSGenericException: VDSNetworkException: Specified netmask or gateway but not ip
2013-02-13 10:59:44,976 ERROR [org.ovirt.engine.core.vdsbroker.VDSCommandBase] (ajp--127.0.0.1-8702-19) [683f2e62] Command SetupNetworksVDS execution failed. Exception: VDSNetworkException: VDSGenericException: VDSNetworkException: Specified netmask or gateway but not ip
2013-02-13 10:59:44,977 ERROR [org.ovirt.engine.core.bll.network.host.SetupNetworksCommand] (ajp--127.0.0.1-8702-19) [683f2e62] Command org.ovirt.engine.core.bll.network.host.SetupNetworksCommand throw Vdc Bll exception. With error message VdcBLLException: org.ovirt.engine.core.vdsbroker.vdsbroker.VDSNetworkException: VDSGenericException: VDSNetworkException: Specified netmask or gateway but not ip
2013-02-13 11:00:00,002 INFO [org.ovirt.engine.core.bll.AutoRecoveryManager] (QuartzScheduler_Worker-3) [33d15439] Autorecovering 1 hosts
2013-02-13 11:00:00,002 INFO [org.ovirt.engine.core.bll.AutoRecoveryManager] (QuartzScheduler_Worker-3) [33d15439] Autorecovering hosts id: 033febb8-4f52-4253-bb6d-a8807816affd, name : KVM-02
2013-02-13 11:00:00,005 INFO [org.ovirt.engine.core.bll.ActivateVdsCommand] (QuartzScheduler_Worker-3) [195b25c6] Lock Acquired to object EngineLock [exclusiveLocks= key: 033febb8-4f52-4253-bb6d-a8807816affd value: VDS
, sharedLocks= ]
2013-02-13 11:00:00,006 INFO [org.ovirt.engine.core.bll.ActivateVdsCommand] (QuartzScheduler_Worker-3) [195b25c6] Running command: ActivateVdsCommand internal: true. Entities affected : ID: 033febb8-4f52-4253-bb6d-a8807816affd Type: VDS
2013-02-13 11:00:00,011 INFO [org.ovirt.engine.core.vdsbroker.SetVdsStatusVDSCommand] (QuartzScheduler_Worker-3) [195b25c6] START, SetVdsStatusVDSCommand(HostName = KVM-02, HostId = 033febb8-4f52-4253-bb6d-a8807816affd, status=Unassigned, nonOperationalReason=NONE), log id: 153fb58f
2013-02-13 11:00:00,013 INFO [org.ovirt.engine.core.vdsbroker.SetVdsStatusVDSCommand] (QuartzScheduler_Worker-3) [195b25c6] FINISH, SetVdsStatusVDSCommand, log id: 153fb58f
2013-02-13 11:00:00,052 INFO [org.ovirt.engine.core.vdsbroker.ActivateVdsVDSCommand] (QuartzScheduler_Worker-3) [195b25c6] START, ActivateVdsVDSCommand(HostName = KVM-02, HostId = 033febb8-4f52-4253-bb6d-a8807816affd), log id: 3f784d25
2013-02-13 11:00:00,176 INFO [org.ovirt.engine.core.vdsbroker.vdsbroker.GetHardwareInfoVDSCommand] (QuartzScheduler_Worker-3) [195b25c6] START, GetHardwareInfoVDSCommand(HostName = KVM-02, HostId = 033febb8-4f52-4253-bb6d-a8807816affd, vds=Host[KVM-02]), log id: 14007e9c
2013-02-13 11:00:00,182 INFO [org.ovirt.engine.core.vdsbroker.vdsbroker.GetHardwareInfoVDSCommand] (QuartzScheduler_Worker-3) [195b25c6] FINISH, GetHardwareInfoVDSCommand, log id: 14007e9c
2013-02-13 11:00:00,316 INFO [org.ovirt.engine.core.bll.SetNonOperationalVdsCommand] (QuartzScheduler_Worker-3) [371c6227] Running command: SetNonOperationalVdsCommand internal: true. Entities affected : ID: 033febb8-4f52-4253-bb6d-a8807816affd Type: VDS
2013-02-13 11:00:00,319 INFO [org.ovirt.engine.core.vdsbroker.SetVdsStatusVDSCommand] (QuartzScheduler_Worker-3) [371c6227] START, SetVdsStatusVDSCommand(HostName = KVM-02, HostId = 033febb8-4f52-4253-bb6d-a8807816affd, status=NonOperational, nonOperationalReason=NETWORK_UNREACHABLE), log id: 62bc0d10
2013-02-13 11:00:00,321 INFO [org.ovirt.engine.core.vdsbroker.SetVdsStatusVDSCommand] (QuartzScheduler_Worker-3) [371c6227] FINISH, SetVdsStatusVDSCommand, log id: 62bc0d10
2013-02-13 11:00:00,322 ERROR [org.ovirt.engine.core.bll.SetNonOperationalVdsCommand] (QuartzScheduler_Worker-3) [371c6227] Host KVM-02 is set to Non-Operational, it is missing the following networks: devvms,WAN_02_02
2013-02-13 11:00:00,377 INFO [org.ovirt.engine.core.bll.HandleVdsCpuFlagsOrClusterChangedCommand] (QuartzScheduler_Worker-3) [3101152] Running command: HandleVdsCpuFlagsOrClusterChangedCommand internal: true. Entities affected : ID: 033febb8-4f52-4253-bb6d-a8807816affd Type: VDS
2013-02-13 11:00:00,382 INFO [org.ovirt.engine.core.bll.HandleVdsVersionCommand] (QuartzScheduler_Worker-3) [657f5a74] Running command: HandleVdsVersionCommand internal: true. Entities affected : ID: 033febb8-4f52-4253-bb6d-a8807816affd Type: VDS
2013-02-13 11:00:00,388 INFO [org.ovirt.engine.core.vdsbroker.ActivateVdsVDSCommand] (QuartzScheduler_Worker-3) [657f5a74] FINISH, ActivateVdsVDSCommand, log id: 3f784d25
2013-02-13 11:00:00,392 WARN [org.ovirt.engine.core.bll.InternalMigrateVmCommand] (pool-3-thread-46) CanDoAction of action InternalMigrateVm failed. Reasons:ACTION_TYPE_FAILED_VM_IS_NON_MIGRTABLE
2013-02-13 11:00:00,393 ERROR [org.ovirt.engine.core.bll.SetNonOperationalVdsCommand] (pool-3-thread-46) ResourceManager::vdsMaintenance - Failed migrating desktop crm-int.office.msp.cullie.local
2013-02-13 11:00:00,458 INFO [org.ovirt.engine.core.bll.ActivateVdsCommand] (QuartzScheduler_Worker-3) [657f5a74] Lock freed to object EngineLock [exclusiveLocks= key: 033febb8-4f52-4253-bb6d-a8807816affd value: VDS
, sharedLocks= ]
2013-02-13 11:00:00,460 INFO [org.ovirt.engine.core.dal.dbbroker.auditloghandling.AuditLogDirector] (QuartzScheduler_Worker-3) [657f5a74] No string for VDS_ACTIVATE_ASYNC type. Use default Log
2013-02-13 11:00:00,462 INFO [org.ovirt.engine.core.bll.AutoRecoveryManager] (QuartzScheduler_Worker-3) [657f5a74] Autorecovering 0 storage domains