Public bug reported: Related LP bug: https://bugs.launchpad.net/neutron/+bug/1865889 Related bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2013820
This bug is related to OVN backend. "segments" service plugin must be enabled. When a new segment is created (for example when a network is created), if this segment is associated to a physnet (flat and vlan type networks) and there is an L2 agent is running on a host with this physnet, a new "SegmentHostMappings" register is created. This segment links this new segment with the host. That means we link a segment with a host when (1) a physnet is mapped in a host and (2) a L2 agent is deployed in this host (and informs about it). In OVN the physnet <-> host mapping is done using the OVS DB [1]: $ ovs-vsctl set open . external-ids:ovn-bridge-mappings=provider:br-provider When an OVS DB is updated, the corresponding OVN SB chassis register is updated. This event is captured in Neutron. Neutron retrieves the current segments associated to the configured physnets (in the example "provider") and filters by network type (flat and vlan only). If any of those segments has no "SegmentHostMappings", a new register is created. However when a new segment is created, OVN mech driver does not correctly check if this segment is located in an agent [2]. Because OVN mech driver has no "agent_type", this method never maps the new created segment with a host. As reported in the bugzilla #2013820, OVN can be deployed with DHCP agents (for baremetal servers with Ironic). When a new network (and the corresponding segment) is created and a new subnet is added to this network, the DHCP agent receives this update. But Neutron server [3] reports this subnet as "non_local_subnets" because there is no mapping between this segment and the DHCP host. Because of this, the DHCP deletes/do not create the DHCP namespace and the DHCP port. [1]https://docs.openstack.org/networking-ovn/2.0.1/refarch/provider-networks.html [2]https://github.com/openstack/neutron/blob/f97baa0b16687453735e46e7a0f73fe03d7d4db7/neutron/plugins/ml2/plugin.py#L2351-L2357 [3]https://github.com/openstack/neutron/blob/9241c76b04e6745cc648ee42037cfe6ddad3600a/neutron/api/rpc/handlers/dhcp_rpc.py#L210-L257 ** Affects: neutron Importance: Undecided Assignee: Rodolfo Alonso (rodolfo-alonso-hernandez) Status: New ** Tags: ovn ** Changed in: neutron Assignee: (unassigned) => Rodolfo Alonso (rodolfo-alonso-hernandez) ** Tags added: ovn -- You received this bug notification because you are a member of Yahoo! Engineering Team, which is subscribed to neutron. https://bugs.launchpad.net/bugs/1949967 Title: [OVN] OVN mech driver does not map new segments Status in neutron: New Bug description: Related LP bug: https://bugs.launchpad.net/neutron/+bug/1865889 Related bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2013820 This bug is related to OVN backend. "segments" service plugin must be enabled. When a new segment is created (for example when a network is created), if this segment is associated to a physnet (flat and vlan type networks) and there is an L2 agent is running on a host with this physnet, a new "SegmentHostMappings" register is created. This segment links this new segment with the host. That means we link a segment with a host when (1) a physnet is mapped in a host and (2) a L2 agent is deployed in this host (and informs about it). In OVN the physnet <-> host mapping is done using the OVS DB [1]: $ ovs-vsctl set open . external-ids:ovn-bridge-mappings=provider:br-provider When an OVS DB is updated, the corresponding OVN SB chassis register is updated. This event is captured in Neutron. Neutron retrieves the current segments associated to the configured physnets (in the example "provider") and filters by network type (flat and vlan only). If any of those segments has no "SegmentHostMappings", a new register is created. However when a new segment is created, OVN mech driver does not correctly check if this segment is located in an agent [2]. Because OVN mech driver has no "agent_type", this method never maps the new created segment with a host. As reported in the bugzilla #2013820, OVN can be deployed with DHCP agents (for baremetal servers with Ironic). When a new network (and the corresponding segment) is created and a new subnet is added to this network, the DHCP agent receives this update. But Neutron server [3] reports this subnet as "non_local_subnets" because there is no mapping between this segment and the DHCP host. Because of this, the DHCP deletes/do not create the DHCP namespace and the DHCP port. [1]https://docs.openstack.org/networking-ovn/2.0.1/refarch/provider-networks.html [2]https://github.com/openstack/neutron/blob/f97baa0b16687453735e46e7a0f73fe03d7d4db7/neutron/plugins/ml2/plugin.py#L2351-L2357 [3]https://github.com/openstack/neutron/blob/9241c76b04e6745cc648ee42037cfe6ddad3600a/neutron/api/rpc/handlers/dhcp_rpc.py#L210-L257 To manage notifications about this bug go to: https://bugs.launchpad.net/neutron/+bug/1949967/+subscriptions -- Mailing list: https://launchpad.net/~yahoo-eng-team Post to : [email protected] Unsubscribe : https://launchpad.net/~yahoo-eng-team More help : https://help.launchpad.net/ListHelp
