Public bug reported: In one of the cloud environment, the FIP attached to the Octavia Loadbalancer VIP is not reachable. After analysis, we found the ARP entry for SNAT IP is missing in the qrouter namespace where Amphora VM is running. And so the return packets are not forwarded from qrouter to snat on active l3-agent node.
Version: Ubuntu Ussuri packages (16.3.2 point release) DVR+SNAT+L3HA enabled Expectation is to have PERMANENT arp entry for snat ip on qrouter namespace on all compute nodes 192.168.33.238 dev qr-4ee692e0-7a lladdr fa:16:3e:25:6a:73 used 38/38/38 probes 0 PERMANENT How to reproduce: Attaching a script to simulate the problem (without octavia) with following steps 1. network/subnet/router is created, network attached to router 2. verify if qrouter on all compute nodes has arp entries related to snat ip 3. if arp entries exists, delete network/subnet/router 4. Repeat steps 1,2,3 until missing arp entry is observed. I am able to reproduce missing arp entry sometimes in 3rd loop and sometimes in 6th loop. Observed arp entries for snat ip is updated at the following places [1] [2] but get_snat_interfaces() and get_ports_by_subnet() are not updated with snat ip in non-working cases. [1] https://opendev.org/openstack/neutron/src/commit/dfd04115b059c2263cdd8ac44ccc2ec47614bcc3/neutron/agent/l3/dvr_local_router.py#L570 [2] https://opendev.org/openstack/neutron/src/commit/dfd04115b059c2263cdd8ac44ccc2ec47614bcc3/neutron/agent/l3/dvr_local_router.py#L317 ** Affects: neutron Importance: Undecided Status: New -- You received this bug notification because you are a member of Yahoo! Engineering Team, which is subscribed to neutron. https://bugs.launchpad.net/bugs/1933092 Title: snat arp entry missing in qrouter namespace Status in neutron: New Bug description: In one of the cloud environment, the FIP attached to the Octavia Loadbalancer VIP is not reachable. After analysis, we found the ARP entry for SNAT IP is missing in the qrouter namespace where Amphora VM is running. And so the return packets are not forwarded from qrouter to snat on active l3-agent node. Version: Ubuntu Ussuri packages (16.3.2 point release) DVR+SNAT+L3HA enabled Expectation is to have PERMANENT arp entry for snat ip on qrouter namespace on all compute nodes 192.168.33.238 dev qr-4ee692e0-7a lladdr fa:16:3e:25:6a:73 used 38/38/38 probes 0 PERMANENT How to reproduce: Attaching a script to simulate the problem (without octavia) with following steps 1. network/subnet/router is created, network attached to router 2. verify if qrouter on all compute nodes has arp entries related to snat ip 3. if arp entries exists, delete network/subnet/router 4. Repeat steps 1,2,3 until missing arp entry is observed. I am able to reproduce missing arp entry sometimes in 3rd loop and sometimes in 6th loop. Observed arp entries for snat ip is updated at the following places [1] [2] but get_snat_interfaces() and get_ports_by_subnet() are not updated with snat ip in non-working cases. [1] https://opendev.org/openstack/neutron/src/commit/dfd04115b059c2263cdd8ac44ccc2ec47614bcc3/neutron/agent/l3/dvr_local_router.py#L570 [2] https://opendev.org/openstack/neutron/src/commit/dfd04115b059c2263cdd8ac44ccc2ec47614bcc3/neutron/agent/l3/dvr_local_router.py#L317 To manage notifications about this bug go to: https://bugs.launchpad.net/neutron/+bug/1933092/+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
