IPV6 service :Router Advertisement (icmpv6_type=134) packets are getting dropped at table=251

Test Topology
===========

VM1 ( OVS-2.6.1) — > Emulated TOR — > External Router

VM2

Steps :

1.VM1 and VM2 getting ipv6 address (slaac mode )from External router through L2gateway configuration
2.IPv6 address is getting assigned on Emulated TOR VMs
3. Router is sending the RA packets to VM1 but it’s getting dropped at table=251.

Note : Please find the attachment with complete flows and also attached the RA packets pcaps which are hitting at tunnel interface before reaching to VM1.

Please find the flows

cookie=0x6900000, duration=1767.935s, table=251, n_packets=0, n_bytes=0, priority=63010,udp,metadata=0x70000000000/0xfffff0000000000,tp_src=67,tp_dst=68 actions=resubmit(,220)
cookie=0x6900000, duration=1767.909s, table=251, n_packets=0, n_bytes=0, priority=63010,udp6,metadata=0x70000000000/0xfffff0000000000,tp_src=547,tp_dst=546 actions=resubmit(,220)
cookie=0x6900000, duration=1767.867s, table=251, n_packets=0, n_bytes=0, priority=63010,icmp6,metadata=0x70000000000/0xfffff0000000000,icmp_type=130,icmp_code=0 actions=resubmit(,220)
cookie=0x6900000, duration=1767.817s, table=251, n_packets=0, n_bytes=0, priority=63010,icmp6,metadata=0x70000000000/0xfffff0000000000,icmp_type=135,icmp_code=0 actions=resubmit(,220)
cookie=0x6900000, duration=1767.743s, table=251, n_packets=4, n_bytes=344, priority=63010,icmp6,metadata=0x70000000000/0xfffff0000000000,icmp_type=136,icmp_code=0 actions=resubmit(,220)
cookie=0x6900000, duration=1761.299s, table=251, n_packets=0, n_bytes=0, priority=63010,udp,metadata=0x80000000000/0xfffff0000000000,tp_src=67,tp_dst=68 actions=resubmit(,220)
cookie=0x6900000, duration=1761.250s, table=251, n_packets=0, n_bytes=0, priority=63010,udp6,metadata=0x80000000000/0xfffff0000000000,tp_src=547,tp_dst=546 actions=resubmit(,220)
cookie=0x6900000, duration=1761.232s, table=251, n_packets=0, n_bytes=0, priority=63010,icmp6,metadata=0x80000000000/0xfffff0000000000,icmp_type=130,icmp_code=0 actions=resubmit(,220)
cookie=0x6900000, duration=1761.190s, table=251, n_packets=0, n_bytes=0, priority=63010,icmp6,metadata=0x80000000000/0xfffff0000000000,icmp_type=135,icmp_code=0 actions=resubmit(,220)
cookie=0x6900000, duration=1761.173s, table=251, n_packets=1, n_bytes=86, priority=63010,icmp6,metadata=0x80000000000/0xfffff0000000000,icmp_type=136,icmp_code=0 actions=resubmit(,220)
cookie=0x6900000, duration=1767.659s, table=251, n_packets=0, n_bytes=0, priority=63010,arp,metadata=0x70000000000/0xfffff0000000000 actions=resubmit(,220)
cookie=0x6900000, duration=1761.131s, table=251, n_packets=0, n_bytes=0, priority=63010,arp,metadata=0x80000000000/0xfffff0000000000 actions=resubmit(,220)
cookie=0x6900000, duration=1767.533s, table=251, n_packets=0, n_bytes=0, priority=61010,ipv6,dl_dst=fa:16:3e:d4:90:e2,ipv6_dst=fe80::f816:3eff:fed4:90e2 actions=ct(table=252,zone=5001)
cookie=0x6900000, duration=1767.441s, table=251, n_packets=0, n_bytes=0, priority=61010,ipv6,dl_dst=fa:16:3e:d4:90:e2,ipv6_dst=2001:db8:1234:0:f816:3eff:fed4:90e2 actions=ct(table=252,zone=5001)
cookie=0x6900000, duration=1761.082s, table=251, n_packets=0, n_bytes=0, priority=61010,ipv6,dl_dst=fa:16:3e:0b:c1:56,ipv6_dst=2001:db8:2345:0:f816:3eff:fe0b:c156 actions=ct(table=252,zone=5002)
cookie=0x6900000, duration=1761.065s, table=251, n_packets=0, n_bytes=0, priority=61010,ipv6,dl_dst=fa:16:3e:0b:c1:56,ipv6_dst=fe80::f816:3eff:fe0b:c156 actions=ct(table=252,zone=5002)
cookie=0x6900000, duration=2583.117s, table=251, n_packets=622, n_bytes=73396, priority=0 actions=drop

Note : If port security is disabled , then issue is not seen and VM1 is getting ipv6 address from external router .