What I did: Shutdown wan6 on the router, wait 10s, Up wan6 on the router, begin capture, wait 10s, unplug my client/notebook, wait 20s, replug my client/notebook, wait 10s, stop.
I hope to show you what's happening with the DHCPv6 on the router of my provider and between my OpenWRT and the client. (I have no filter active on the Allow-DHCPv6 rule).
root@OpenWrt:/etc/config# ifdown wan6; sleep 10; ifup wan6; tcpdump -i eth1.2 -evn icmp6 or udp port 546
tcpdump: listening on eth1.2, link-type EN10MB (Ethernet), capture size 262144 bytes
16:11:16.089856 60:38:e0:d7:72:93 > 33:33:00:01:00:02, ethertype IPv6 (0x86dd), length 164: (flowlabel 0xa45ce, hlim 1, next-header UDP (17) payload length: 110) fe80::6238:e0ff:fed7:7293.546 > ff02::1:2.547: [bad udp cksum 0xb2a9 -> 0x50d0!] dhcp6 solicit (xid=d3beae (elapsed-time 0) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list SNTP-servers NTP-server AFTR-Name opt_67 opt_94 opt_95 opt_96 opt_82) (client-ID hwaddr type 1 6038e0d77293) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:1 T1:0 T2:0) (IA_PD IAID:1 T1:0 T2:0))
16:11:16.166756 00:04:96:8b:8c:8d > 60:38:e0:d7:72:93, ethertype IPv6 (0x86dd), length 237: (hlim 64, next-header UDP (17) payload length: 183) 2a01:71a0:8000:1::3.547 > fe80::6238:e0ff:fed7:7293.546: [udp sum ok] dhcp6 advertise (xid=d3beae (client-ID hwaddr type 1 6038e0d77293) (server-ID hwaddr/time type 1 time 625652870 005056a5d054) (IA_NA IAID:1 T1:0 T2:21600 (IA_ADDR 2a01:71a0:8000:1:0:d:0:129f pltime:43200 vltime:86400)) (DNS-server 2a01:71a0:40:53::53 2a01:71a0:40:53::1:53) (IA_PD IAID:1 T1:0 T2:21600 (IA_PD-prefix 2a01:71a0:8012:a300::/56 pltime:43200 vltime:86400)) (Client-FQDN))
16:11:16.167864 00:04:96:8b:8c:8d > 60:38:e0:d7:72:93, ethertype IPv6 (0x86dd), length 237: (hlim 64, next-header UDP (17) payload length: 183) 2a01:71a0:8000:1::3.547 > fe80::6238:e0ff:fed7:7293.546: [udp sum ok] dhcp6 advertise (xid=d3beae (client-ID hwaddr type 1 6038e0d77293) (server-ID hwaddr/time type 1 time 625653035 005056a54e8b) (IA_NA IAID:1 T1:0 T2:21600 (IA_ADDR 2a01:71a0:8000:1:0:d:0:129f pltime:43200 vltime:86400)) (DNS-server 2a01:71a0:40:53::53 2a01:71a0:40:53::1:53) (IA_PD IAID:1 T1:0 T2:21600 (IA_PD-prefix 2a01:71a0:8012:a300::/56 pltime:43200 vltime:86400)) (Client-FQDN))
16:11:16.168914 00:04:96:52:8f:b1 > 60:38:e0:d7:72:93, ethertype IPv6 (0x86dd), length 237: (hlim 64, next-header UDP (17) payload length: 183) 2a01:71a0:8000:1::2.547 > fe80::6238:e0ff:fed7:7293.546: [udp sum ok] dhcp6 advertise (xid=d3beae (client-ID hwaddr type 1 6038e0d77293) (server-ID hwaddr/time type 1 time 625653035 005056a54e8b) (IA_NA IAID:1 T1:0 T2:21600 (IA_ADDR 2a01:71a0:8000:1:0:d:0:12a0 pltime:43200 vltime:86400)) (DNS-server 2a01:71a0:40:53::53 2a01:71a0:40:53::1:53) (IA_PD IAID:1 T1:0 T2:21600 (IA_PD-prefix 2a01:71a0:8012:a400::/56 pltime:43200 vltime:86400)) (Client-FQDN))
16:11:16.170076 00:04:96:52:8f:b1 > 60:38:e0:d7:72:93, ethertype IPv6 (0x86dd), length 237: (hlim 64, next-header UDP (17) payload length: 183) 2a01:71a0:8000:1::2.547 > fe80::6238:e0ff:fed7:7293.546: [udp sum ok] dhcp6 advertise (xid=d3beae (client-ID hwaddr type 1 6038e0d77293) (server-ID hwaddr/time type 1 time 625652870 005056a5d054) (IA_NA IAID:1 T1:0 T2:21600 (IA_ADDR 2a01:71a0:8000:1:0:d:0:12a0 pltime:43200 vltime:86400)) (DNS-server 2a01:71a0:40:53::53 2a01:71a0:40:53::1:53) (IA_PD IAID:1 T1:0 T2:21600 (IA_PD-prefix 2a01:71a0:8012:a400::/56 pltime:43200 vltime:86400)) (Client-FQDN))
16:11:16.366578 00:00:5e:00:02:02 > 33:33:00:00:00:01, ethertype IPv6 (0x86dd), length 150: (hlim 255, next-header ICMPv6 (58) payload length: 96) fe80::5e00:202 > ff02::1: [icmp6 sum ok] ICMP6, router advertisement, length 96
hop limit 64, Flags [managed], pref medium, router lifetime 1800s, reachable time 30000ms, retrans timer 1000ms
source link-address option (1), length 8 (1): 00:00:5e:00:02:02
prefix info option (3), length 32 (4): 2a01:71a0:8000:1::/64, Flags [onlink, auto], valid time 2592000s, pref. time 604800s
rdnss option (25), length 40 (5): lifetime 1200s, addr: 2a01:71a0:40:53::53 addr: 2a01:71a0:40:53::1:53
16:11:18.163665 60:38:e0:d7:72:93 > 33:33:00:01:00:02, ethertype IPv6 (0x86dd), length 237: (flowlabel 0xa45ce, hlim 1, next-header UDP (17) payload length: 183) fe80::6238:e0ff:fed7:7293.546 > ff02::1:2.547: [bad udp cksum 0xb2f2 -> 0xc6fb!] dhcp6 request (xid=4bb6a7 (elapsed-time 0) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list SNTP-servers NTP-server AFTR-Name opt_67 opt_94 opt_95 opt_96) (client-ID hwaddr type 1 6038e0d77293) (server-ID hwaddr/time type 1 time 625653035 005056a54e8b) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:1 T1:0 T2:0 (IA_ADDR 2a01:71a0:8000:1:0:d:0:12a0 pltime:43200 vltime:86400)) (IA_PD IAID:1 T1:0 T2:0 (IA_PD-prefix 2a01:71a0:8012:a400::/56 pltime:43200 vltime:86400)))
16:11:18.182380 00:04:96:8b:8c:8d > 60:38:e0:d7:72:93, ethertype IPv6 (0x86dd), length 237: (hlim 64, next-header UDP (17) payload length: 183) 2a01:71a0:8000:1::3.547 > fe80::6238:e0ff:fed7:7293.546: [udp sum ok] dhcp6 reply (xid=4bb6a7 (client-ID hwaddr type 1 6038e0d77293) (server-ID hwaddr/time type 1 time 625653035 005056a54e8b) (IA_NA IAID:1 T1:0 T2:21600 (IA_ADDR 2a01:71a0:8000:1:0:d:0:12a0 pltime:43200 vltime:86400)) (DNS-server 2a01:71a0:40:53::53 2a01:71a0:40:53::1:53) (IA_PD IAID:1 T1:0 T2:21600 (IA_PD-prefix 2a01:71a0:8012:a400::/56 pltime:43200 vltime:86400)) (Client-FQDN))
16:11:18.521532 60:38:e0:d7:72:93 > 33:33:ff:d7:72:93, ethertype IPv6 (0x86dd), length 86: (hlim 255, next-header ICMPv6 (58) payload length: 32) :: > ff02::1:ffd7:7293: [icmp6 sum ok] ICMP6, neighbor solicitation, length 32, who has 2a01:71a0:8000:1:6238:e0ff:fed7:7293
unknown option (14), length 8 (1):
0x0000: 3315 2992 d2ce
16:11:18.526181 00:04:96:8b:8c:8d > 33:33:ff:00:00:bf, ethertype IPv6 (0x86dd), length 86: (hlim 255, next-header ICMPv6 (58) payload length: 32) fe80::204:96ff:fe8b:8c8d > ff02::1:ff00:bf: [icmp6 sum ok] ICMP6, neighbor solicitation, length 32, who has 2a01:71a0:8000:1:0:d:0:bf
source link-address option (1), length 8 (1): 00:04:96:8b:8c:8d
16:11:18.991537 60:38:e0:d7:72:93 > 33:33:ff:00:12:a0, ethertype IPv6 (0x86dd), length 86: (hlim 255, next-header ICMPv6 (58) payload length: 32) :: > ff02::1:ff00:12a0: [icmp6 sum ok] ICMP6, neighbor solicitation, length 32, who has 2a01:71a0:8000:1:0:d:0:12a0
unknown option (14), length 8 (1):
0x0000: deb6 79e0 0c52
16:11:21.395808 00:04:96:8b:8c:8d > 33:33:ff:d7:72:93, ethertype IPv6 (0x86dd), length 86: (hlim 255, next-header ICMPv6 (58) payload length: 32) fe80::204:96ff:fe8b:8c8d > ff02::1:ffd7:7293: [icmp6 sum ok] ICMP6, neighbor solicitation, length 32, who has fe80::6238:e0ff:fed7:7293
source link-address option (1), length 8 (1): 00:04:96:8b:8c:8d
16:11:21.395856 60:38:e0:d7:72:93 > 00:04:96:8b:8c:8d, ethertype IPv6 (0x86dd), length 86: (hlim 255, next-header ICMPv6 (58) payload length: 32) fe80::6238:e0ff:fed7:7293 > fe80::204:96ff:fe8b:8c8d: [icmp6 sum ok] ICMP6, neighbor advertisement, length 32, tgt is fe80::6238:e0ff:fed7:7293, Flags [router, solicited, override]
destination link-address option (2), length 8 (1): 60:38:e0:d7:72:93
16:11:22.116407 00:04:96:8b:8c:8d > 33:33:ff:e0:4c:c9, ethertype IPv6 (0x86dd), length 86: (hlim 255, next-header ICMPv6 (58) payload length: 32) fe80::204:96ff:fe8b:8c8d > ff02::1:ffe0:4cc9: [icmp6 sum ok] ICMP6, neighbor solicitation, length 32, who has 2a01:71a0:8000:1:18e:4a93:5be0:4cc9
source link-address option (1), length 8 (1): 00:04:96:8b:8c:8d
16:11:26.431533 60:38:e0:d7:72:93 > 00:04:96:8b:8c:8d, ethertype IPv6 (0x86dd), length 86: (hlim 255, next-header ICMPv6 (58) payload length: 32) fe80::6238:e0ff:fed7:7293 > fe80::204:96ff:fe8b:8c8d: [icmp6 sum ok] ICMP6, neighbor solicitation, length 32, who has fe80::204:96ff:fe8b:8c8d
source link-address option (1), length 8 (1): 60:38:e0:d7:72:93
16:11:26.433730 00:04:96:8b:8c:8d > 60:38:e0:d7:72:93, ethertype IPv6 (0x86dd), length 78: (hlim 255, next-header ICMPv6 (58) payload length: 24) fe80::204:96ff:fe8b:8c8d > fe80::6238:e0ff:fed7:7293: [icmp6 sum ok] ICMP6, neighbor advertisement, length 24, tgt is fe80::204:96ff:fe8b:8c8d, Flags [router, solicited]
16:11:28.388751 60:38:e0:d7:72:93 > 00:00:5e:00:02:02, ethertype IPv6 (0x86dd), length 578: (flowlabel 0x720ba, hlim 64, next-header ICMPv6 (58) payload length: 524) 2a01:71a0:8000:1:6238:e0ff:fed7:7293 > 2a01:71a0:40:53::1:53: [icmp6 sum ok] ICMP6, destination unreachable, unreachable port, 2a01:71a0:8000:1:6238:e0ff:fed7:7293 udp port 8899
16:11:34.056951 00:04:96:8b:8c:8d > 33:33:ff:00:00:6e, ethertype IPv6 (0x86dd), length 86: (hlim 255, next-header ICMPv6 (58) payload length: 32) fe80::204:96ff:fe8b:8c8d > ff02::1:ff00:6e: [icmp6 sum ok] ICMP6, neighbor solicitation, length 32, who has 2a01:71a0:8000:1:0:d:0:6e
source link-address option (1), length 8 (1): 00:04:96:8b:8c:8d
16:11:35.016807 00:04:96:8b:8c:8d > 33:33:ff:00:00:06, ethertype IPv6 (0x86dd), length 86: (hlim 255, next-header ICMPv6 (58) payload length: 32) fe80::204:96ff:fe8b:8c8d > ff02::1:ff00:6: [icmp6 sum ok] ICMP6, neighbor solicitation, length 32, who has 2a01:71a0:8000:1:0:d:0:6
source link-address option (1), length 8 (1): 00:04:96:8b:8c:8d
16:11:39.206854 00:04:96:8b:8c:8d > 33:33:ff:00:00:14, ethertype IPv6 (0x86dd), length 86: (hlim 255, next-header ICMPv6 (58) payload length: 32) fe80::204:96ff:fe8b:8c8d > ff02::1:ff00:14: [icmp6 sum ok] ICMP6, neighbor solicitation, length 32, who has 2a01:71a0:8000:1:0:d:0:14
source link-address option (1), length 8 (1): 00:04:96:8b:8c:8d
16:11:40.273511 00:04:96:52:8f:b1 > 33:33:ff:83:f9:67, ethertype IPv6 (0x86dd), length 86: (hlim 255, next-header ICMPv6 (58) payload length: 32) fe80::204:96ff:fe52:8fb1 > ff02::1:ff83:f967: [icmp6 sum ok] ICMP6, neighbor solicitation, length 32, who has fe80::618:d6ff:fe83:f967
source link-address option (1), length 8 (1): 00:04:96:52:8f:b1
16:11:48.191530 60:38:e0:d7:72:93 > 00:00:5e:00:02:02, ethertype IPv6 (0x86dd), length 86: (hlim 255, next-header ICMPv6 (58) payload length: 32) fe80::6238:e0ff:fed7:7293 > fe80::5e00:202: [icmp6 sum ok] ICMP6, neighbor solicitation, length 32, who has fe80::5e00:202
source link-address option (1), length 8 (1): 60:38:e0:d7:72:93
16:11:48.193838 00:04:96:8b:8c:8d > 60:38:e0:d7:72:93, ethertype IPv6 (0x86dd), length 78: (hlim 255, next-header ICMPv6 (58) payload length: 24) fe80::5e00:202 > fe80::6238:e0ff:fed7:7293: [icmp6 sum ok] ICMP6, neighbor advertisement, length 24, tgt is fe80::5e00:202, Flags [router, solicited]
16:11:50.324021 60:38:e0:d7:72:93 > 00:00:5e:00:02:02, ethertype IPv6 (0x86dd), length 576: (flowlabel 0x720ba, hlim 64, next-header ICMPv6 (58) payload length: 522) 2a01:71a0:8000:1:6238:e0ff:fed7:7293 > 2a01:71a0:40:53::1:53: [icmp6 sum ok] ICMP6, destination unreachable, unreachable port, 2a01:71a0:8000:1:6238:e0ff:fed7:7293 udp port 39468
16:11:54.694130 00:04:96:52:8f:b1 > 33:33:ff:d6:f2:ce, ethertype IPv6 (0x86dd), length 86: (hlim 255, next-header ICMPv6 (58) payload length: 32) fe80::204:96ff:fe52:8fb1 > ff02::1:ffd6:f2ce: [icmp6 sum ok] ICMP6, neighbor solicitation, length 32, who has fe80::f2b0:14ff:fed6:f2ce
source link-address option (1), length 8 (1): 00:04:96:52:8f:b1
16:11:56.377447 00:04:96:8b:8c:8d > 33:33:ff:00:00:2b, ethertype IPv6 (0x86dd), length 86: (hlim 255, next-header ICMPv6 (58) payload length: 32) fe80::204:96ff:fe8b:8c8d > ff02::1:ff00:2b: [icmp6 sum ok] ICMP6, neighbor solicitation, length 32, who has 2a01:71a0:8000:1:0:d:0:2b
source link-address option (1), length 8 (1): 00:04:96:8b:8c:8d
16:12:01.187480 00:04:96:8b:8c:8d > 33:33:ff:00:00:b3, ethertype IPv6 (0x86dd), length 86: (hlim 255, next-header ICMPv6 (58) payload length: 32) fe80::204:96ff:fe8b:8c8d > ff02::1:ff00:b3: [icmp6 sum ok] ICMP6, neighbor solicitation, length 32, who has 2a01:71a0:8000:1:0:d:0:b3
source link-address option (1), length 8 (1): 00:04:96:8b:8c:8d
^C
27 packets captured
29 packets received by filter
0 packets dropped by kernel
Thanks for your patience and time.
Greenoid