Hi, I have problem with IPv6 IP.
After reboot my MikroTik IPv6 is working corectly but afer few minutes RouterOS stops send neighbor-advertisement to gateway.
I use /126 IPv6 network to connect with my ISP.
Please help
After more thorough verification, the problem is with no sending neighbor advertisement packet.
After a few minutes after I add IPv6 address RouterOS stops send neighbor advertisement.
The only solution is disable and enable IPv6 address.
But on link-local address communication works all time.
MikroTik have Internet via untag (ether1) interface.
This is tcpdump from host whose is a gateway for MikroTik:
tcpdump -i vlan3799 -ne -s0 ip6
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on vlan3799, link-type EN10MB (Ethernet), capture size 262144 bytes
18:01:44.181185 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 11520, length 16
18:01:44.181217 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:01:45.182509 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 11776, length 16
18:01:45.183403 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:01:46.183906 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 12032, length 16
18:01:46.223431 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:01:47.184894 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 12288, length 16
18:01:48.186450 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 12544, length 16
18:01:48.186499 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:01:49.187914 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 12800, length 16
18:01:49.263428 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:01:50.189555 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 13056, length 16
18:01:50.303402 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:01:51.191064 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 13312, length 16
18:01:52.192529 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 13568, length 16
18:01:52.192597 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:01:53.193961 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 13824, length 16
18:01:53.263435 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:01:54.194873 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 14080, length 16
18:01:54.303433 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:01:55.196232 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 14336, length 16
18:01:56.197583 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 14592, length 16
18:01:56.197632 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:01:57.198961 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 14848, length 16
18:01:57.263420 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:01:58.200441 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 15104, length 16
18:01:58.303406 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:01:59.194527 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 86: fe80::bcda:8aff:feb3:5da4 > 2a00:c020::f:25: ICMP6, neighbor solicitation, who has 2a00:c020::f:25, length 32
18:01:59.194576 00:25:90:93:62:50 > be:da:8a:b3:5d:a4, ethertype IPv6 (0x86dd), length 78: 2a00:c020::f:25 > fe80::bcda:8aff:feb3:5da4: ICMP6, neighbor advertisement, tgt is 2a00:c020::f:25, length 24
18:01:59.201699 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 15360, length 16
18:02:00.203056 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 15616, length 16
18:02:00.203135 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:02:01.204534 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 15872, length 16
18:02:01.263413 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:02:02.205989 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 16128, length 16
18:02:02.303383 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:02:03.207384 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 16384, length 16
18:02:04.208926 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 16640, length 16
18:02:04.208976 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:02:04.223419 00:25:90:93:62:50 > be:da:8a:b3:5d:a4, ethertype IPv6 (0x86dd), length 86: fe80::225:90ff:fe93:6250 > fe80::bcda:8aff:feb3:5da4: ICMP6, neighbor solicitation, who has fe80::bcda:8aff:feb3:5da4, length 32
18:02:04.223560 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 78: fe80::bcda:8aff:feb3:5da4 > fe80::225:90ff:fe93:6250: ICMP6, neighbor advertisement, tgt is fe80::bcda:8aff:feb3:5da4, length 24
18:02:05.210383 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 16896, length 16
18:02:05.263380 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:02:06.211785 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 17152, length 16
18:02:06.303383 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:02:07.213192 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 17408, length 16
18:02:08.214689 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 17664, length 16
18:02:08.214735 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:02:09.214459 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 86: fe80::bcda:8aff:feb3:5da4 > fe80::225:90ff:fe93:6250: ICMP6, neighbor solicitation, who has fe80::225:90ff:fe93:6250, length 32
18:02:09.214516 00:25:90:93:62:50 > be:da:8a:b3:5d:a4, ethertype IPv6 (0x86dd), length 78: fe80::225:90ff:fe93:6250 > fe80::bcda:8aff:feb3:5da4: ICMP6, neighbor advertisement, tgt is fe80::225:90ff:fe93:6250, length 24
18:02:09.216053 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 17920, length 16
18:02:09.263400 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:02:10.217507 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 18176, length 16
18:02:10.303398 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:02:11.218972 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 18432, length 16
18:02:12.220356 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 18688, length 16
18:02:12.220420 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:02:13.221803 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 18944, length 16
18:02:13.263421 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:02:13.375049 be:da:8a:b3:5d:a4 > 33:33:00:00:00:16, ethertype IPv6 (0x86dd), length 110: fe80::bcda:8aff:feb3:5da4 > ff02::16: HBH ICMP6, multicast listener report v2, 2 group record(s), length 48
18:02:14.303420 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
In this moment I disable and enable IPv6 address
18:02:18.975002 be:da:8a:b3:5d:a4 > 33:33:00:00:00:16, ethertype IPv6 (0x86dd), length 170: fe80::bcda:8aff:feb3:5da4 > ff02::16: HBH ICMP6, multicast listener report v2, 5 group record(s), length 108
18:02:19.004881 be:da:8a:b3:5d:a4 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 78: :: > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 24
18:02:19.155274 be:da:8a:b3:5d:a4 > 33:33:00:00:00:16, ethertype IPv6 (0x86dd), length 150: fe80::bcda:8aff:feb3:5da4 > ff02::16: HBH ICMP6, multicast listener report v2, 4 group record(s), length 88
18:02:20.025003 be:da:8a:b3:5d:a4 > 33:33:00:00:00:16, ethertype IPv6 (0x86dd), length 90: fe80::bcda:8aff:feb3:5da4 > ff02::16: HBH ICMP6, multicast listener report v2, 1 group record(s), length 28
18:02:21.222430 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 20992, length 16
18:02:21.222479 00:25:90:93:62:50 > 33:33:ff:0f:00:26, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:25 > ff02::1:ff0f:26: ICMP6, neighbor solicitation, who has 2a00:c020::f:26, length 32
18:02:21.223023 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 86: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, neighbor advertisement, tgt is 2a00:c020::f:26, length 32
18:02:21.223030 00:25:90:93:62:50 > be:da:8a:b3:5d:a4, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:25 > 2a00:c020::f:26: ICMP6, echo reply, seq 20992, length 16
18:02:22.224524 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 21248, length 16
18:02:22.224538 00:25:90:93:62:50 > be:da:8a:b3:5d:a4, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:25 > 2a00:c020::f:26: ICMP6, echo reply, seq 21248, length 16
18:02:23.226091 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 21504, length 16
18:02:23.226108 00:25:90:93:62:50 > be:da:8a:b3:5d:a4, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:25 > 2a00:c020::f:26: ICMP6, echo reply, seq 21504, length 16
18:02:24.227865 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 21760, length 16
18:02:24.227883 00:25:90:93:62:50 > be:da:8a:b3:5d:a4, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:25 > 2a00:c020::f:26: ICMP6, echo reply, seq 21760, length 16
18:02:25.229530 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 22016, length 16
18:02:25.229571 00:25:90:93:62:50 > be:da:8a:b3:5d:a4, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:25 > 2a00:c020::f:26: ICMP6, echo reply, seq 22016, length 16
18:02:26.231040 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 22272, length 16
18:02:26.231075 00:25:90:93:62:50 > be:da:8a:b3:5d:a4, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:25 > 2a00:c020::f:26: ICMP6, echo reply, seq 22272, length 16
18:02:27.232633 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 22528, length 16
18:02:27.232648 00:25:90:93:62:50 > be:da:8a:b3:5d:a4, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:25 > 2a00:c020::f:26: ICMP6, echo reply, seq 22528, length 16
18:02:28.234207 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 22784, length 16
18:02:28.234222 00:25:90:93:62:50 > be:da:8a:b3:5d:a4, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:25 > 2a00:c020::f:26: ICMP6, echo reply, seq 22784, length 16
18:02:29.215111 be:da:8a:b3:5d:a4 > 33:33:00:00:00:16, ethertype IPv6 (0x86dd), length 90: fe80::bcda:8aff:feb3:5da4 > ff02::16: HBH ICMP6, multicast listener report v2, 1 group record(s), length 28
18:02:29.225841 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 23040, length 16
18:02:29.225859 00:25:90:93:62:50 > be:da:8a:b3:5d:a4, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:25 > 2a00:c020::f:26: ICMP6, echo reply, seq 23040, length 16
18:02:30.227490 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 23296, length 16
18:02:30.227525 00:25:90:93:62:50 > be:da:8a:b3:5d:a4, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:25 > 2a00:c020::f:26: ICMP6, echo reply, seq 23296, length 16
18:02:31.229204 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 23552, length 16
18:02:31.229223 00:25:90:93:62:50 > be:da:8a:b3:5d:a4, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:25 > 2a00:c020::f:26: ICMP6, echo reply, seq 23552, length 16
18:02:32.230807 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 23808, length 16
18:02:32.230842 00:25:90:93:62:50 > be:da:8a:b3:5d:a4, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:25 > 2a00:c020::f:26: ICMP6, echo reply, seq 23808, length 16
18:02:33.232305 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 24064, length 16
18:02:33.232340 00:25:90:93:62:50 > be:da:8a:b3:5d:a4, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:25 > 2a00:c020::f:26: ICMP6, echo reply, seq 24064, length 16
18:02:34.233899 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 24320, length 16
18:02:34.233932 00:25:90:93:62:50 > be:da:8a:b3:5d:a4, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:25 > 2a00:c020::f:26: ICMP6, echo reply, seq 24320, length 16
18:02:35.234475 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 24576, length 16
18:02:35.234504 00:25:90:93:62:50 > be:da:8a:b3:5d:a4, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:25 > 2a00:c020::f:26: ICMP6, echo reply, seq 24576, length 16
18:02:36.224407 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 86: fe80::bcda:8aff:feb3:5da4 > 2a00:c020::f:25: ICMP6, neighbor solicitation, who has 2a00:c020::f:25, length 32
18:02:36.224427 00:25:90:93:62:50 > be:da:8a:b3:5d:a4, ethertype IPv6 (0x86dd), length 78: 2a00:c020::f:25 > fe80::bcda:8aff:feb3:5da4: ICMP6, neighbor advertisement, tgt is 2a00:c020::f:25, length 24
18:02:36.236146 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 24832, length 16
18:02:36.236180 00:25:90:93:62:50 > be:da:8a:b3:5d:a4, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:25 > 2a00:c020::f:26: ICMP6, echo reply, seq 24832, length 16
18:02:37.237695 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 25088, length 16
18:02:37.237728 00:25:90:93:62:50 > be:da:8a:b3:5d:a4, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:25 > 2a00:c020::f:26: ICMP6, echo reply, seq 25088, length 16
18:02:38.239280 be:da:8a:b3:5d:a4 > 00:25:90:93:62:50, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:26 > 2a00:c020::f:25: ICMP6, echo request, seq 25344, length 16
18:02:38.239298 00:25:90:93:62:50 > be:da:8a:b3:5d:a4, ethertype IPv6 (0x86dd), length 70: 2a00:c020::f:25 > 2a00:c020::f:26: ICMP6, echo reply, seq 25344, length 16
^C
106 packets captured
124 packets received by filter
Neighbor table (when communication doesn’t work) look like this:
ip -6 neigh show dev vlan3799
2a00:c020::f:26 FAILED
fe80::bcda:8aff:feb3:5da4 lladdr be:da:8a:b3:5d:a4 router REACHABLE
Problem has been solved 
Virtualization proxmox on which the virtual machine with RouterOS has been enabled has IGMP Snnoping turned on by default, which cut these packages.
The solution to disable IGMP Snnoping on a specific bridge is:
echo 1 > /sys/devices/virtual/net/bridge/bridge/multicast_querier
echo 0 > /sys/devices/virtual/net/bridge/bridge/multicast_snooping
Where bridge is name of bridge is the name of the bridge that we use to communicate with the virtual machine.