Comment 0 for bug 1967856

If you have two hvs where hv1 is the gateway chassis and you have an instance running on hv2.

On instance on hv2 hairpin traffic works for the first session, but not for the next:

$ ping -c1 10.78.95.89
PING 10.78.95.89 (10.78.95.89) 56(84) bytes of data.
64 bytes from 10.78.95.89: icmp_seq=1 ttl=62 time=1.07 ms

--- 10.78.95.89 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 1.078/1.078/1.078/0.000 ms

$ sudo ovs-appctl -t ovs-vswitchd dpctl/dump-conntrack
icmp,orig=(src=10.78.95.89,dst=192.168.0.211,id=7334,type=8,code=0),reply=(src=192.168.0.211,dst=10.78.95.89,id=7334,type=0,code=0),zone=7
icmp,orig=(src=192.168.0.211,dst=10.78.95.89,id=7334,type=8,code=0),reply=(src=10.78.95.89,dst=192.168.0.211,id=7334,type=0,code=0),zone=7

$ ping -c1 10.78.95.89
PING 10.78.95.89 (10.78.95.89) 56(84) bytes of data.

--- 10.78.95.89 ping statistics ---
1 packets transmitted, 0 received, 100% packet loss, time 0ms

$ sudo ovs-appctl -t ovs-vswitchd dpctl/dump-conntrack
icmp,orig=(src=10.78.95.89,dst=192.168.0.211,id=7334,type=8,code=0),reply=(src=192.168.0.211,dst=10.78.95.89,id=7334,type=0,code=0),zone=7
icmp,orig=(src=192.168.0.211,dst=10.78.95.89,id=7334,type=8,code=0),reply=(src=10.78.95.89,dst=192.168.0.211,id=7334,type=0,code=0),zone=7
icmp,orig=(src=192.168.0.211,dst=10.78.95.89,id=7335,type=8,code=0),reply=(src=10.78.95.89,dst=192.168.0.211,id=7335,type=0,code=0),zone=7

We made an attempt at using OVN built with [0], but that did unfortunately not help.

If we however revert [1] it works again:
$ ping -c1 10.78.95.89
PING 10.78.95.89 (10.78.95.89) 56(84) bytes of data.
64 bytes from 10.78.95.89: icmp_seq=1 ttl=62 time=1.31 ms

--- 10.78.95.89 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 1.318/1.318/1.318/0.000 ms

$ sudo ovs-appctl -t ovs-vswitchd dpctl/dump-conntrack
icmp,orig=(src=192.168.0.211,dst=10.78.95.89,id=7336,type=8,code=0),reply=(src=10.78.95.89,dst=192.168.0.211,id=7336,type=0,code=0),zone=7
icmp,orig=(src=10.78.95.89,dst=192.168.0.211,id=7336,type=8,code=0),reply=(src=192.168.0.211,dst=10.78.95.89,id=7336,type=0,code=0),zone=7
icmp,orig=(src=10.78.95.89,dst=192.168.0.211,id=7336,type=8,code=0),reply=(src=192.168.0.211,dst=10.78.95.89,id=7336,type=0,code=0),zone=1

$ ping -c1 10.78.95.89
PING 10.78.95.89 (10.78.95.89) 56(84) bytes of data.
64 bytes from 10.78.95.89: icmp_seq=1 ttl=62 time=0.307 ms

--- 10.78.95.89 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.307/0.307/0.307/0.000 ms

$ sudo ovs-appctl -t ovs-vswitchd dpctl/dump-conntrack
icmp,orig=(src=10.78.95.89,dst=192.168.0.211,id=7337,type=8,code=0),reply=(src=192.168.0.211,dst=10.78.95.89,id=7337,type=0,code=0),zone=7
icmp,orig=(src=10.78.95.89,dst=192.168.0.211,id=7337,type=8,code=0),reply=(src=192.168.0.211,dst=10.78.95.89,id=7337,type=0,code=0),zone=1
icmp,orig=(src=192.168.0.211,dst=10.78.95.89,id=7337,type=8,code=0),reply=(src=10.78.95.89,dst=192.168.0.211,id=7337,type=0,code=0),zone=7
icmp,orig=(src=192.168.0.211,dst=10.78.95.89,id=7336,type=8,code=0),reply=(src=10.78.95.89,dst=192.168.0.211,id=7336,type=0,code=0),zone=7
icmp,orig=(src=10.78.95.89,dst=192.168.0.211,id=7336,type=8,code=0),reply=(src=192.168.0.211,dst=10.78.95.89,id=7336,type=0,code=0),zone=7
icmp,orig=(src=10.78.95.89,dst=192.168.0.211,id=7336,type=8,code=0),reply=(src=192.168.0.211,dst=10.78.95.89,id=7336,type=0,code=0),zone=1

0: https://patchwork<email address hidden>/
1: https://github.com/ovn-org/ovn/commit/4deac4509abbedd6ffaecf27eed01ddefccea40a