root@OpenWrt:~# tcpdump -i eth0.2 -n -vv '(udp port 546 or 547) or icmp6'
tcpdump: listening on eth0.2, link-type EN10MB (Ethernet), capture size 262144 bytes
21:03:49.565965 IP6 (flowlabel 0xbb3da, hlim 255, next-header ICMPv6 (58) payload length: 16) fe80::fad1:11ff:fe64:676f > ff02::2: [icmp6 sum ok] ICMP6, rout
er solicitation, length 16
          source link-address option (1), length 8 (1): f8:d1:11:64:67:6f
            0x0000:  f8d1 1164 676f
21:03:49.568705 IP6 (class 0xc0, hlim 255, next-header ICMPv6 (58) payload length: 64) fe80::768e:f8ff:fe63:26 > ff02::1: [icmp6 sum ok] ICMP6, router advertisement, length 64
        hop limit 64, Flags [none], pref medium, router lifetime 1800s, reachable time 0s, retrans time 0s
          source link-address option (1), length 8 (1): 74:8e:f8:63:5f:81
            0x0000:  748e f863 5f81
          mtu option (5), length 8 (1):  1500
            0x0000:  0000 0000 05dc
          prefix info option (3), length 32 (4): 2a01:<redacted>::/64, Flags [onlink, auto], valid time 2592000s, pref. time 604800s
            0x0000:  40c0 0027 8d00 0009 3a80 0000 0000 2a01
            0x0010:  6e00 0001 0001 0000 0000 0000 0000
21:03:50.184218 IP6 (flowlabel 0xae88c, hlim 1, next-header UDP (17) payload length: 114) fe80::fad1:11ff:fe64:676f.546 > ff02::1:2.547: [udp sum ok] dhcp6 solicit (xid=f7bd6f (elapsed-time 0) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list server-unicast SNTP-servers NTP-server AFTR-Name opt_67 opt_82 opt_83 opt_94 opt_95 opt_96) (client-ID hwaddr type 1 f8d11164676f) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:1 T1:0 T2:0) (IA_PD IAID:1 T1:0 T2:0))
21:03:51.276297 IP6 (flowlabel 0xae88c, hlim 1, next-header UDP (17) payload length: 114) fe80::fad1:11ff:fe64:676f.546 > ff02::1:2.547: [udp sum ok] dhcp6 solicit (xid=f7bd6f (elapsed-time 109) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list server-unicast SNTP-servers NTP-server AFTR-Name opt_67 opt_82 opt_83 opt_94 opt_95 opt_96) (client-ID hwaddr type 1 f8d11164676f) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:1 T1:0 T2:0) (IA_PD IAID:1 T1:0 T2:0))
21:03:53.435894 IP6 (flowlabel 0xae88c, hlim 1, next-header UDP (17) payload length: 114) fe80::fad1:11ff:fe64:676f.546 > ff02::1:2.547: [udp sum ok] dhcp6 solicit (xid=f7bd6f (elapsed-time 325) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list server-unicast SNTP-servers NTP-server AFTR-Name opt_67 opt_82 opt_83 opt_94 opt_95 opt_96) (client-ID hwaddr type 1 f8d11164676f) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:1 T1:0 T2:0) (IA_PD IAID:1 T1:0 T2:0))
21:03:57.595756 IP6 (flowlabel 0xae88c, hlim 1, next-header UDP (17) payload length: 114) fe80::fad1:11ff:fe64:676f.546 > ff02::1:2.547: [udp sum ok] dhcp6 solicit (xid=f7bd6f (elapsed-time 741) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list server-unicast SNTP-servers NTP-server AFTR-Name opt_67 opt_82 opt_83 opt_94 opt_95 opt_96) (client-ID hwaddr type 1 f8d11164676f) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:1 T1:0 T2:0) (IA_PD IAID:1 T1:0 T2:0))
21:04:00.446241 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 24) :: > ff02::1:ff64:676f: [icmp6 sum ok] ICMP6, neighbor solicitation, length 24, who has 2a01:<redacted>:676f
21:04:05.515797 IP6 (flowlabel 0xae88c, hlim 1, next-header UDP (17) payload length: 114) fe80::fad1:11ff:fe64:676f.546 > ff02::1:2.547: [udp sum ok] dhcp6 solicit (xid=f7bd6f (elapsed-time 1533) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list server-unicast SNTP-servers NTP-server AFTR-Name opt_67 opt_82 opt_83 opt_94 opt_95 opt_96) (client-ID hwaddr type 1 f8d11164676f) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:1 T1:0 T2:0) (IA_PD IAID:1 T1:0 T2:0))
21:04:21.275877 IP6 (flowlabel 0xae88c, hlim 1, next-header UDP (17) payload length: 114) fe80::fad1:11ff:fe64:676f.546 > ff02::1:2.547: [udp sum ok] dhcp6 solicit (xid=f7bd6f (elapsed-time 3109) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list server-unicast SNTP-servers NTP-server AFTR-Name opt_67 opt_82 opt_83 opt_94 opt_95 opt_96) (client-ID hwaddr type 1 f8d11164676f) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:1 T1:0 T2:0) (IA_PD IAID:1 T1:0 T2:0))
21:04:22.264582 IP6 (hlim 64, next-header UDP (17) payload length: 54) fe80::7644:1ff:fe36:4a55.546 > ff02::1:2.547: [udp sum ok] dhcp6 solicit (xid=75edfd (client-ID hwaddr type 1 744401364a55) (elapsed-time 65535) (IA_PD IAID:11 T1:0 T2:0) (option-request DNS-server))
21:04:31.822019 IP6 (hlim 1, next-header UDP (17) payload length: 113) fe80::821f:2ff:fedd:1db9.546 > ff02::1:2.547: [udp sum ok] dhcp6 solicit (xid=1b642a (elapsed-time 65535) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list SNTP-servers NTP-server AFTR-Name opt_67 opt_82 opt_83 opt_94 opt_95 opt_96) (client-ID hwaddr type 1 801f02dd1db9) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:1 T1:0 T2:0) (IA_PD IAID:1 T1:0 T2:0))
21:04:47.349620 IP6 (hlim 1, next-header UDP (17) payload length: 112) fe80::fad1:11ff:fe54:e397.546 > ff02::1:2.547: [udp sum ok] dhcp6 solicit (xid=2cefec (elapsed-time 65535) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list SNTP-servers NTP-server AFTR-Name opt_67 opt_82 opt_83 opt_94 opt_95 opt_96) (client-ID hwaddr type 1 f8d11154e397) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:1 T1:0 T2:0) (IA_PD IAID:1 T1:0 T2:0))
21:04:51.995819 IP6 (flowlabel 0xae88c, hlim 1, next-header UDP (17) payload length: 114) fe80::fad1:11ff:fe64:676f.546 > ff02::1:2.547: [udp sum ok] dhcp6 solicit (xid=f7bd6f (elapsed-time 6181) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list server-unicast SNTP-servers NTP-server AFTR-Name opt_67 opt_82 opt_83 opt_94 opt_95 opt_96) (client-ID hwaddr type 1 f8d11164676f) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:1 T1:0 T2:0) (IA_PD IAID:1 T1:0 T2:0))