Comment 2 for bug 1928330

I tried to reproduce but couldn't, i did on master devstack env:-

openstack security group create basic
openstack security group rule create basic --protocol tcp --dst-port 22:22 --remote-ip 0.0.0.0/0
openstack security group rule create basic --protocol tcp --dst-port 22:22 --ethertype ipv6
openstack security group rule create --protocol icmp basic
openstack security group rule create --protocol icmp basic --ethertype ipv6
openstack security group rule create --protocol udp --dst-port 53:53 basic

test -f ~/.ssh/id_rsa.pub || ssh-keygen -t rsa -N "" -f ~/.ssh/id_rsa
openstack keypair create --public-key ~/.ssh/id_rsa.pub default
# nova flavor
openstack flavor create --ram 512 --disk 1 --vcpu 1 --public tiny

openstack network create ipv6-pd
openstack subnet create --ip-version 6 --ipv6-ra-mode slaac --ipv6-address-mode slaac --network ipv6-pd --gateway 2001:db8:2222:d1c::1 --allocation-pool=start=2001:db8:2222:d1c::2,end=2001:db8:2222:d1c:ffff:ffff:ffff:ffff ipv6-pd-1 --subnet-range 2001:db8:2222:d1c::/64
openstack router add subnet router1 ipv6-pd-1

openstack server create --nic net-id=ipv6-pd --image cirros-0.5.2-x86_64-disk --security-group basic --key-name default --flavor tiny testvm

$ openstack port list --network ipv6-pd
/usr/lib/python3/dist-packages/secretstorage/dhcrypto.py:15: CryptographyDeprecationWarning: int_from_bytes is deprecated, use int.from_bytes instead
  from cryptography.utils import int_from_bytes
/usr/lib/python3/dist-packages/secretstorage/util.py:19: CryptographyDeprecationWarning: int_from_bytes is deprecated, use int.from_bytes instead
  from cryptography.utils import int_from_bytes
+--------------------------------------+------+-------------------+-----------------------------------------------------------------------------------------------------+--------+
| ID | Name | MAC Address | Fixed IP Addresses | Status |
+--------------------------------------+------+-------------------+-----------------------------------------------------------------------------------------------------+--------+
| 4e0179bb-1dbd-46bb-b86e-935224889858 | | fa:16:3e:7b:2b:b6 | ip_address='2001:db8:2222:d1c::1', subnet_id='db9e25b3-9a51-488a-b257-658351e928c6' | ACTIVE |
| dc7ef71d-ec1d-44eb-be9f-fb2c67f6cac2 | | fa:16:3e:51:0b:fa | ip_address='2001:db8:2222:d1c:f816:3eff:fe51:bfa', subnet_id='db9e25b3-9a51-488a-b257-658351e928c6' | ACTIVE |
| f7de9144-45c4-4664-bf91-eb4048de1670 | | fa:16:3e:bd:06:e0 | ip_address='2001:db8:2222:d1c:f816:3eff:febd:6e0', subnet_id='db9e25b3-9a51-488a-b257-658351e928c6' | DOWN |
+--------------------------------------+------+-------------------+-----------------------------------------------------------------------------------------------------+--------+

From vm:-
$ ping 2001:db8:2222:d1c::1
PING 2001:db8:2222:d1c::1 (2001:db8:2222:d1c::1): 56 data bytes
64 bytes from 2001:db8:2222:d1c::1: seq=0 ttl=254 time=2.191 ms
64 bytes from 2001:db8:2222:d1c::1: seq=1 ttl=254 time=0.785 ms
64 bytes from 2001:db8:2222:d1c::1: seq=2 ttl=254 time=0.834 ms
^C
--- 2001:db8:2222:d1c::1 ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max = 0.785/1.270/2.191 ms

$ sudo ovn-trace ipv6-pd 'inport == "dc7ef71d-ec1d-44eb-be9f-fb2c67f6cac2" && eth.src == fa:16:3e:51:0b:fa && eth.dst == fa:16:3e:65:02:e9 && ip6.src == 2001:db8:2222:d1c:f816:3eff:fe51:bfa && ip6.dst == 2001:db8:2222:d1c::1'
# ipv6,reg14=0x3,vlan_tci=0x0000,dl_src=fa:16:3e:51:0b:fa,dl_dst=fa:16:3e:65:02:e9,ipv6_src=2001:db8:2222:d1c:f816:3eff:fe51:bfa,ipv6_dst=2001:db8
:2222:d1c::1,ipv6_label=0x00000,nw_proto=0,nw_tos=0,nw_ecn=0,nw_ttl=0

ingress(dp="ipv6-pd", inport="dc7ef7")
--------------------------------------
 0. ls_in_port_sec_l2 (northd.c:5205): inport == "dc7ef7" && eth.src == {fa:16:3e:51:0b:fa}, priority 50, uuid af10c8f9
    next;
 1. ls_in_port_sec_ip (northd.c:4868): inport == "dc7ef7" && eth.src == fa:16:3e:51:0b:fa && ip6.src == {fe80::f816:3eff:fe51:bfa, 2001:db8:2222:d
1c:f816:3eff:fe51:bfa}, priority 90, uuid 956e95d5
    next;
 5. ls_in_pre_acl (northd.c:5463): ip, priority 100, uuid 7f9b5be9
    reg0[0] = 1;
    next;
 7. ls_in_pre_stateful (northd.c:5669): reg0[0] == 1, priority 100, uuid 2fdb9eda
    ct_next;

ct_next(ct_state=est|trk /* default (use --ct to customize) */)
---------------------------------------------------------------
 8. ls_in_acl_hint (northd.c:5748): !ct.new && ct.est && !ct.rpl && ct_label.blocked == 0, priority 4, uuid 5b28b009
    reg0[8] = 1;
    reg0[10] = 1;
    next;
 9. ls_in_acl (northd.c:5974): reg0[8] == 1 && (inport == @pg_32cb109b_1eda_4a3b_b3e5_2269b388b6f1 && ip6), priority 2002, uuid d03ea4c0
    next; 22. ls_in_l2_lkup (northd.c:8034): eth.dst == fa:16:3e:65:02:e9, priority 50, uuid 89615973
    outport = "536736";
    output;
egress(dp="ipv6-pd", inport="dc7ef7", outport="536736") [265/1998]-------------------------------------------------------
 0. ls_out_pre_lb (northd.c:5355): ip && outport == "536736", priority 110, uuid c0d52ba8
    next;
 1. ls_out_pre_acl (northd.c:5355): ip && outport == "536736", priority 110, uuid 88fed770
    next;
 3. ls_out_acl_hint (northd.c:5748): !ct.new && ct.est && !ct.rpl && ct_label.blocked == 0, priority 4, uuid ea31d707
    reg0[8] = 1;
    reg0[10] = 1;
    next;
 9. ls_out_port_sec_l2 (northd.c:5302): outport == "536736", priority 50, uuid f81bc41d
    output;
    /* output to "536736", type "patch" */

ingress(dp="router1", inport="lrp-536736")
------------------------------------------
 0. lr_in_admission (northd.c:10271): eth.dst == fa:16:3e:65:02:e9 && inport == "lrp-536736", priority 50, uuid 6d7cecd6
    xreg0[0..47] = fa:16:3e:65:02:e9;
    next;
 1. lr_in_lookup_neighbor (northd.c:10352): 1, priority 0, uuid 6438693f
    reg9[2] = 1;
    next;
 2. lr_in_learn_neighbor (northd.c:10361): reg9[2] == 1 || reg9[3] == 0, priority 100, uuid 4004d6b9
    next;
 3. lr_in_ip_input (northd.c:10048): ip6.dst == {2001:db8:2222:d1c::1, fe80::f816:3eff:fe65:2e9}, priority 60, uuid 4a85be6b
    drop;

Can you confirm if the above tests are correct, or need to try some other operations to reproduce the issue?