Hello, Sorry for the late response. We encountered again the same issue and I managed to do again the workaround steps. So the faulty VM is on compute-40. Here are all the namespaces configured on this compute node. [root@compute-40 ~]# ip netns fip-bb27c880-c0ac-4941-9aa2-70de032cbb7c (id: 5) qrouter-7413152f-8b53-4bc5-bdb0-ca936f7aee17 (id: 2) qrouter-9b2225f1-b8ba-4079-8441-6e3d599fafb1 (id: 0) qrouter-0786134b-55a4-4549-99e1-d0f34a7bf897 (id: 1) qrouter-7e060fb5-ca41-4d29-9cac-48f353509208 (id: 3) qrouter-48248482-9412-444c-84e8-ece4309bb7a0 (id: 4) Our namespace is the following: [root@compute-40 ~]# ip netns exec qrouter-9b2225f1-b8ba-4079-8441-6e3d599fafb1 bash [root@compute-40 ~]# ip r 10.10.13.0/24 dev qr-4affa6db-67 proto kernel scope link src 10.10.13.1 169.254.127.96/31 dev rfp-9b2225f1-b proto kernel scope link src 169.254.127.96 [root@compute-40 ~]# ip a 1: lo: mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: rfp-9b2225f1-b@if5: mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether c2:12:6b:27:29:bd brd ff:ff:ff:ff:ff:ff link-netns fip-bb27c880-c0ac-4941-9aa2-70de032cbb7c inet 169.254.127.96/31 scope global rfp-9b2225f1-b valid_lft forever preferred_lft forever inet6 fe80::c012:6bff:fe27:29bd/64 scope link valid_lft forever preferred_lft forever 58: qr-4affa6db-67: mtu 1450 qdisc noqueue state UNKNOWN group default qlen 1000 link/ether fa:16:3e:e4:a6:aa brd ff:ff:ff:ff:ff:ff inet 10.10.13.1/24 brd 10.10.13.255 scope global qr-4affa6db-67 valid_lft forever preferred_lft forever inet6 fe80::f816:3eff:fee4:a6aa/64 scope link valid_lft forever preferred_lft forever The IP of the VM is 10.10.13.195. When I try to ping it, it does not answer and I have the PERM arp entry for it. [root@compute-40 ~]# ping 10.10.13.195 PING 10.10.13.195 (10.10.13.195) 56(84) bytes of data. ^C --- 10.10.13.195 ping statistics --- 5 packets transmitted, 0 received, 100% packet loss, time 78ms [root@compute-40 ~]# arp -a | grep 10.10.13.195 ? (10.10.13.195) at fa:16:3e:c5:b9:23 [ether] PERM on qr-4affa6db-67 After I delete the arp entry the VM is starting to answer to ping and it's changing the arp entry. [root@compute-40 ~]# arp -d 10.10.13.195 [root@compute-40 ~]# ping 10.10.13.195 PING 10.10.13.195 (10.10.13.195) 56(84) bytes of data. 64 bytes from 10.10.13.195: icmp_seq=1 ttl=64 time=1.24 ms 64 bytes from 10.10.13.195: icmp_seq=2 ttl=64 time=0.394 ms 64 bytes from 10.10.13.195: icmp_seq=3 ttl=64 time=0.319 ms 64 bytes from 10.10.13.195: icmp_seq=4 ttl=64 time=0.363 ms ^C --- 10.10.13.195 ping statistics --- 4 packets transmitted, 4 received, 0% packet loss, time 41ms rtt min/avg/max/mdev = 0.319/0.578/1.238/0.382 ms [root@compute-40 ~]# arp -a | grep 10.10.13.195 ? (10.10.13.195) at fa:16:3e:a4:76:8c [ether] on qr-4affa6db-67 So... I am not sure what log files to look for. Can you guys give me a hint. I could not find any errors in the /var/lib/docker/volumes/kolla_logs/_data/neutron/neutron-openvswitch-agent.log Here are the logs when it created the VM with IP 10.10.13.195. 2021-05-06 05:24:13.719 7 INFO neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [req-bf4aba68-1d9e-466e-bf56-c2ec4da5399d - - - - -] Port 019390bb-8e74-468d-aa12-bc2952038ec5 updated. Details: {'device': '019390bb-8e74-468d-aa12-bc2952038ec5', 'device_id': '2d6daa0a-6e8a-4f18-8de7-f7c6e1e09419', 'network_id': 'a5486dd5-ad9f-4ae0-8922-6a2e70c17f7c', 'port_id': '019390bb-8e74-468d-aa12-bc2952038ec5', 'mac_address': 'fa:16:3e:a4:76:8c', 'admin_state_up': True, 'network_type': 'vxlan', 'segmentation_id': 7, 'physical_network': None, 'fixed_ips': [{'subnet_id': '5224c1a8-5e7d-4e65-bc3c-82a27693b8ea', 'ip_address': '10.10.13.195'}], 'device_owner': 'compute:nova', 'allowed_address_pairs': [], 'port_security_enabled': True, 'qos_policy_id': None, 'network_qos_policy_id': None, 'profile': {}, 'vif_type': 'ovs', 'vnic_type': 'normal', 'security_groups': ['78f32d1a-ee3d-49be-b6cc-f4bc8ce706a0']} 2021-05-06 05:24:13.725 7 INFO neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [req-bf4aba68-1d9e-466e-bf56-c2ec4da5399d - - - - -] process_network_ports - iteration:261173 - treat_devices_added_or_updated completed. Skipped 0 and no activated binding devices 0 of 16 devices currently available. Time elapsed: 0.011 2021-05-06 05:24:13.730 7 INFO neutron.agent.securitygroups_rpc [req-bf4aba68-1d9e-466e-bf56-c2ec4da5399d - - - - -] Preparing filters for devices {'019390bb-8e74-468d-aa12-bc2952038ec5'} 2021-05-06 05:24:16.103 7 INFO neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [req-bf4aba68-1d9e-466e-bf56-c2ec4da5399d - - - - -] process_network_ports - iteration:261173 - agent port security group processed in 2.388 2021-05-06 05:24:16.779 7 INFO neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [req-bf4aba68-1d9e-466e-bf56-c2ec4da5399d - - - - -] Configuration for devices up ['019390bb-8e74-468d-aa12-bc2952038ec5'] and devices down [] completed. 2021-05-06 05:24:16.779 7 INFO neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [req-bf4aba68-1d9e-466e-bf56-c2ec4da5399d - - - - -] Agent rpc_loop - iteration:261173 - ports processed. Elapsed:3.076 2021-05-06 05:24:16.780 7 INFO neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [req-bf4aba68-1d9e-466e-bf56-c2ec4da5399d - - - - -] Agent rpc_loop - iteration:261173 completed. Processed ports statistics: {'regular': {'added': 1, 'updated': 1, 'removed': 0}}. Elapsed:3.076 2021-05-06 05:24:16.780 7 INFO neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [req-bf4aba68-1d9e-466e-bf56-c2ec4da5399d - - - - -] Agent rpc_loop - iteration:261174 started 2021-05-06 05:24:16.783 7 INFO neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [req-bf4aba68-1d9e-466e-bf56-c2ec4da5399d - - - - -] Agent rpc_loop - iteration:261174 - starting polling. Elapsed:0.003 2021-05-06 05:24:16.788 7 INFO neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [req-bf4aba68-1d9e-466e-bf56-c2ec4da5399d - - - - -] Agent rpc_loop - iteration:261174 - port information retrieved. Elapsed:0.008 2021-05-06 05:24:16.792 7 INFO neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [req-bf4aba68-1d9e-466e-bf56-c2ec4da5399d - - - - -] Port 019390bb-8e74-468d-aa12-bc2952038ec5 updated. Details: {'device': '019390bb-8e74-468d-aa12-bc2952038ec5', 'device_id': '2d6daa0a-6e8a-4f18-8de7-f7c6e1e09419', 'network_id': 'a5486dd5-ad9f-4ae0-8922-6a2e70c17f7c', 'port_id': '019390bb-8e74-468d-aa12-bc2952038ec5', 'mac_address': 'fa:16:3e:a4:76:8c', 'admin_state_up': True, 'network_type': 'vxlan', 'segmentation_id': 7, 'physical_network': None, 'fixed_ips': [{'subnet_id': '5224c1a8-5e7d-4e65-bc3c-82a27693b8ea', 'ip_address': '10.10.13.195'}], 'device_owner': 'compute:nova', 'allowed_address_pairs': [], 'port_security_enabled': True, 'qos_policy_id': None, 'network_qos_policy_id': None, 'profile': {}, 'vif_type': 'ovs', 'vnic_type': 'normal', 'security_groups': ['78f32d1a-ee3d-49be-b6cc-f4bc8ce706a0']} 2021-05-06 05:24:16.795 7 INFO neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [req-bf4aba68-1d9e-466e-bf56-c2ec4da5399d - - - - -] process_network_ports - iteration:261174 - treat_devices_added_or_updated completed. Skipped 0 and no activated binding devices 0 of 16 devices currently available. Time elapsed: 0.006 2021-05-06 05:24:16.796 7 INFO neutron.agent.securitygroups_rpc [req-bf4aba68-1d9e-466e-bf56-c2ec4da5399d - - - - -] Refresh firewall rules 2021-05-06 05:24:16.862 7 INFO neutron.agent.securitygroups_rpc [req-c0b62724-e2cd-4d23-ac17-1906f1d5a07c 742a6700df704ffdbb29c0f73c57adae fa7cc4c1af894b7e92b 8d0726f10d548 - - -] Security group member updated {'78f32d1a-ee3d-49be-b6cc-f4bc8ce706a0', 'a808fd6a-dc24-433d-9b4d-e2680be38aba'} 2021-05-06 05:24:17.436 7 INFO neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [req-bf4aba68-1d9e-466e-bf56-c2ec4da5399d - - - - -] process_network_ports - iteration:261174 - agent port security group processed in 0.647 2021-05-06 05:24:17.917 7 INFO neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [req-bf4aba68-1d9e-466e-bf56-c2ec4da5399d - - - - -] Configuration for devices up ['019390bb-8e74-468d-aa12-bc2952038ec5'] and devices down [] completed. 2021-05-06 05:24:17.918 7 INFO neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [req-bf4aba68-1d9e-466e-bf56-c2ec4da5399d - - - - -] Agent rpc_loop - iteration:261174 - ports processed. Elapsed:1.138 2021-05-06 05:24:17.918 7 INFO neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [req-bf4aba68-1d9e-466e-bf56-c2ec4da5399d - - - - -] Agent rpc_loop - iteration:261174 completed. Processed ports statistics: {'regular': {'added': 0, 'updated': 1, 'removed': 0}}. Elapsed:1.138 2021-05-06 05:24:18.781 7 INFO neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [req-bf4aba68-1d9e-466e-bf56-c2ec4da5399d - - - - -] Agent rpc_loop - iteration:261175 started 2021-05-06 05:24:18.784 7 INFO neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [req-bf4aba68-1d9e-466e-bf56-c2ec4da5399d - - - - -] Agent rpc_loop - iteration:261175 - starting polling. Elapsed:0.003 2021-05-06 05:24:18.791 7 INFO neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [req-bf4aba68-1d9e-466e-bf56-c2ec4da5399d - - - - -] Agent rpc_loop - iteration:261175 - port information retrieved. Elapsed:0.010 2021-05-06 05:24:18.796 7 INFO neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [req-bf4aba68-1d9e-466e-bf56-c2ec4da5399d - - - - -] Port 019390bb-8e74-468d-aa12-bc2952038ec5 updated. Details: {'device': '019390bb-8e74-468d-aa12-bc2952038ec5', 'device_id': '2d6daa0a-6e8a-4f18-8de7-f7c6e1e09419', 'network_id': 'a5486dd5-ad9f-4ae0-8922-6a2e70c17f7c', 'port_id': '019390bb-8e74-468d-aa12-bc2952038ec5', 'mac_address': 'fa:16:3e:a4:76:8c', 'admin_state_up': True, 'network_type': 'vxlan', 'segmentation_id': 7, 'physical_network': None, 'fixed_ips': [{'subnet_id': '5224c1a8-5e7d-4e65-bc3c-82a27693b8ea', 'ip_address': '10.10.13.195'}], 'device_owner': 'compute:nova', 'allowed_address_pairs': [], 'port_security_enabled': True, 'qos_policy_id': None, 'network_qos_policy_id': None, 'profile': {}, 'vif_type': 'ovs', 'vnic_type': 'normal', 'security_groups': ['78f32d1a-ee3d-49be-b6cc-f4bc8ce706a0', 'a808fd6a-dc24-433d-9b4d-e2680be38aba']} 2021-05-06 05:24:18.799 7 INFO neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [req-bf4aba68-1d9e-466e-bf56-c2ec4da5399d - - - - -] process_network_ports - iteration:261175 - treat_devices_added_or_updated completed. Skipped 0 and no activated binding devices 0 of 16 devices currently available. Time elapsed: 0.007 If you need any config files/other logs, please let me know and I can provide you. Thanks! Andrei Panescu