IPv6 issues after sysupgrade

sppmaster · October 28, 2025, 6:21pm

I've updated my self compiled Main OpenWrt build a few hours ago up to this commit.
Upon reboot IPv6 can no longer be connected.
I get this error message.

[Oct 28, 2025, 8:05:43 daemon.warn: odhcp6c[23012]: Server returned IA_PD status 'No Address Available (No addresses have been assigned)'
[Oct 28, 2025, 8:05:45 daemon.warn: odhcp6c[23012]: Server returned IA_PD status 'No Address Available (No addresses have been assigned)'
[Oct 28, 2025, 8:05:47 daemon.warn: odhcp6c[23012]: Server returned IA_PD status 'No Address Available (No addresses have been assigned)'
[Oct 28, 2025, 8:05:49 daemon.warn: odhcp6c[23012]: Server returned IA_PD status 'No Address Available (No addresses have been assigned)'

I see there are several recent updates to odhcp6c.
Can anyone help with this?
Thanks.

_bernd · October 28, 2025, 6:23pm

How does your wan network and DHCP config look?

sppmaster · October 28, 2025, 6:32pm


config interface 'loopback'
	option device 'lo'
	option proto 'static'
	list ipaddr '127.0.0.1/8'

config globals 'globals'
	option packet_steering '0'

config device
	option name 'br-lan'
	option type 'bridge'
	list ports '10g-copper'
	list ports '10g-sfp'
	list ports 'lan1'
	list ports 'lan2'
	list ports 'lan4'
	list ports 'lan5'
	list ports 'lan6'
	list ports 'lan7'
	list ports 'lan8'

config interface 'lan'
	option device 'br-lan'
	option proto 'static'
	option ip6assign '64'
	list ipaddr '192.168.1.1/24'
	list ip6class 'wan6'

config interface 'wan'
	option device 'wan'
	option proto 'dhcp'
	option hostname '*'

config interface 'wan6'
	option device 'wan'
	option proto 'dhcpv6'
	option reqaddress 'try'
	option reqprefix 'auto'
	option norelease '1'
	list ip6class 'wan6'

config dnsmasq
	option domainneeded '1'
	option localise_queries '1'
	option rebind_protection '1'
	option rebind_localhost '1'
	option local '/lan/'
	option domain 'lan'
	option expandhosts '1'
	option cachesize '1000'
	option authoritative '1'
	option readethers '1'
	option leasefile '/tmp/dhcp.leases'
	option localservice '1'
	option ednspacket_max '1232'
	option sequential_ip '1'
	list rebind_domain 'dns.msftncsi.com'
	list server '/mask.icloud.com/'
	list server '/mask-h2.icloud.com/'
	list server '/use-application-dns.net/'
	list server '127.0.0.1#5053'
	option doh_backup_noresolv '-1'
	option noresolv '1'
	list doh_backup_server '/mask.icloud.com/'
	list doh_backup_server '/mask-h2.icloud.com/'
	list doh_backup_server '/use-application-dns.net/'
	list doh_backup_server '127.0.0.1#5053'
	list doh_server '127.0.0.1#5053'
	option serversfile '/var/run/adblock-fast/dnsmasq.servers'
	list addnmount '/var/run/pbr.dnsmasq'

config dhcp 'lan'
	option interface 'lan'
	option start '100'
	option limit '50'
	option leasetime '48h'
	option dhcpv4 'server'
	option dhcpv6 'server'
	option ra 'server'
	list ra_flags 'managed-config'
	list ra_flags 'other-config'
	option force '1'

config dhcp 'wan'
	option interface 'wan'
	option ignore '1'

config odhcpd 'odhcpd'
	option maindhcp '0'
	option leasefile '/tmp/hosts/odhcpd'
	option leasetrigger '/usr/sbin/odhcpd-update'
	option loglevel '4'
	option piofolder '/tmp/odhcpd-piofolder'

root@Asus:~# uci show network.wan6
network.wan6=interface
network.wan6.device='wan'
network.wan6.proto='dhcpv6'
network.wan6.reqaddress='try'
network.wan6.reqprefix='auto'
network.wan6.norelease='1'
network.wan6.ip6class='wan6'
root@Asus:~# uci show network.wan
network.wan=interface
network.wan.device='wan'
network.wan.proto='dhcp'
network.wan.hostname='*'
root@Asus:~# ifstatus wan6
{
        "up": false,
        "pending": true,
        "available": true,
        "autostart": true,
        "dynamic": false,
        "proto": "dhcpv6",
        "device": "wan",
        "data": {

        }
}

systemcrash · October 28, 2025, 8:17pm

Run:

. /lib/functions/network.sh
network_get_physdev l2device wan6
tcpdump -vX -i $l2device "((icmp6 and ip6[40] == 134) or (udp port 546 and port 547))"

and hit restart for the wan6 interface in the GUI.

sppmaster · October 28, 2025, 9:34pm

tcpdump: listening on wan, link-type EN10MB (Ethernet), snapshot length 262144 bytes
00:11:53.864755 IP6 (flowlabel 0x72bfd, hlim 1, next-header UDP (17) payload length: 99) fe80::642:1aff:fee4:d11d.546 > ff02::1:2.547: [bad udp cksum 0xef3e -> 0x90fc!] dhcp6 solicit (xid=9f9597 (elapsed-time 0) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list SNTP-servers NTP-server opt_67 opt_82) (client-ID hwaddr type 1 xxxxxxxxxxxx) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:6 T1:0 T2:0) (IA_PD IAID:1 T1:0 T2:0))
        0x0000:  6007 2bfd 0063 1101 fe80 0000 0000 0000  `.+..c..........
        0x0010:  0642 1aff fee4 d11d ff02 0000 0000 0000  .B..............
        0x0020:  0000 0000 0001 0002 0222 0223 0063 ef3e  .........".#.c.>
        0x0030:  019f 9597 0008 0002 0000 0006 0010 0015  ................
        0x0040:  0016 0017 0018 001f 0038 0043 0052 0001  .........8.C.R..
        0x0050:  000a 0003 0001 0442 1ae4 d11d 0014 0000  .......B........
        0x0060:  0027 0007 0004 4173 7573 0000 0300 0c00  .'....Asus......
        0x0070:  0000 0600 0000 0000 0000 0000 1900 0c00  ................
        0x0080:  0000 0100 0000 0000 0000 00              ...........
00:11:53.904666 IP6 (class 0xc0, hlim 255, next-header UDP (17) payload length: 165) fe80::a2f3:e4ff:fe81:fe30.547 > fe80::642:1aff:fee4:d11d.546: [udp sum ok] dhcp6 advertise (xid=9f9597 (server-ID hwaddr type 1 mac_1) (client-ID hwaddr type 1 xxxxxxxxxxxx) (IA_NA IAID:6 T1:300 T2:400 (IA_ADDR xaab-xbb8-30e-1982--1.v6.ispnamemasked.com pltime:600 vltime:600)) (IA_PD IAID:1 T1:1800 T2:2880 (IA_PD-prefix xaab-xbb8-x99e-xx--.v6.ispnamemasked.com/64 pltime:3600 vltime:86400)) (DNS-server xaab-xbb8--6-42.v6.ispnamemasked.com xaab-xbb8--6-43.v6.ispnamemasked.com))
        0x0000:  6c00 0000 00a5 11ff fe80 0000 0000 0000  l...............
        0x0010:  a2f3 e4ff fe81 fe30 fe80 0000 0000 0000  .......0........
        0x0020:  0642 1aff fee4 d11d 0223 0222 00a5 994d  .B.......#."...M
        0x0030:  029f 9597 0002 000a 0003 0001 10e8 7872  ..............xr
        0x0040:  6f51 0001 000a 0003 0001 0442 1ae4 d11d  oQ.........B....
        0x0050:  0003 0028 0000 0006 0000 012c 0000 0190  ...(.......,....
        0x0060:  0005 0018 2a01 05a8 030e 1982 0000 0000  ....*...........
        0x0070:  0000 0001 0000 0258 0000 0258 0019 0029  .......X...X...)
        0x0080:  0000 0001 0000 0708 0000 0b40 001a 0019  ...........@....
        0x0090:  0000 0e10 0001 5180 402a 0105 a803 0e09  ......Q.@*......
        0x00a0:  9500 0000 0000 0000 0000 1700 202a 0105  .............*..
        0x00b0:  a800 0000 0000 0000 0000 0600 422a 0105  ............B*..
        0x00c0:  a800 0000 0000 0000 0000 0600 43         ............C
00:11:54.524484 IP6 (class 0xc0, hlim 255, next-header ICMPv6 (58) payload length: 24) fe80::a2f3:e4ff:fe81:fe30 > fe80::642:1aff:fee4:d11d: [icmp6 sum ok] ICMP6, router advertisement, length 24
        hop limit 64, Flags [managed], pref medium, router lifetime 4500s, reachable time 0ms, retrans timer 0ms
          source link-address option (1), length 8 (1): 00:00:5e:00:01:13
        0x0000:  6c00 0000 0018 3aff fe80 0000 0000 0000  l.....:.........
        0x0010:  a2f3 e4ff fe81 fe30 fe80 0000 0000 0000  .......0........
        0x0020:  0642 1aff fee4 d11d 8600 5498 4080 1194  .B........T.@...
        0x0030:  0000 0000 0000 0000 0101 0000 5e00 0113  ............^...
00:11:54.905626 IP6 (flowlabel 0x72bfd, hlim 1, next-header UDP (17) payload length: 168) fe80::642:1aff:fee4:d11d.546 > ff02::1:2.547: [bad udp cksum 0xef83 -> 0xe9b2!] dhcp6 request (xid=210130 (elapsed-time 0) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list SNTP-servers NTP-server opt_67) (client-ID hwaddr type 1 xxxxxxxxxxxx) (server-ID hwaddr type 1 mac_1) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:6 T1:0 T2:0 (IA_ADDR xaab-xbb8-30e-1982--1.v6.ispnamemasked.com pltime:600 vltime:600)) (IA_PD IAID:1 T1:0 T2:0 (IA_PD-prefix xaab-xbb8-x99e-xx--.v6.ispnamemasked.com/64 pltime:3600 vltime:86400)))
        0x0000:  6007 2bfd 00a8 1101 fe80 0000 0000 0000  `.+.............
        0x0010:  0642 1aff fee4 d11d ff02 0000 0000 0000  .B..............
        0x0020:  0000 0000 0001 0002 0222 0223 00a8 ef83  .........".#....
        0x0030:  0321 0130 0008 0002 0000 0006 000e 0015  .!.0............
        0x0040:  0016 0017 0018 001f 0038 0043 0001 000a  .........8.C....
        0x0050:  0003 0001 0442 1ae4 d11d 0002 000a 0003  .....B..........
        0x0060:  0001 10e8 7872 6f51 0014 0000 0027 0007  ....xroQ.....'..
        0x0070:  0004 4173 7573 0000 0300 2800 0000 0600  ..Asus....(.....
        0x0080:  0000 0000 0000 0000 0500 182a 0105 a803  ...........*....
        0x0090:  0e19 8200 0000 0000 0000 0100 0002 5800  ..............X.
        0x00a0:  0002 5800 1900 2900 0000 0100 0000 0000  ..X...).........
        0x00b0:  0000 0000 1a00 1900 000e 1000 0151 8040  .............Q.@
        0x00c0:  2a01 05a8 030e 0995 0000 0000 0000 0000  *...............
00:11:54.944725 IP6 (class 0xc0, hlim 255, next-header UDP (17) payload length: 174) fe80::a2f3:e4ff:fe81:fe30.547 > fe80::642:1aff:fee4:d11d.546: [udp sum ok] dhcp6 reply (xid=210130 (server-ID hwaddr type 1 mac_1) (client-ID hwaddr type 1 xxxxxxxxxxxx) (IA_NA IAID:6 T1:0 T2:0 (status-code NoAddrsAvail)) (IA_PD IAID:1 T1:1800 T2:2880 (IA_PD-prefix xaab-xbb8-x99e-xx--.v6.ispnamemasked.com/64 pltime:3600 vltime:86400)) (DNS-server xaab-xbb8--6-42.v6.ispnamemasked.com xaab-xbb8--6-43.v6.ispnamemasked.com))
        0x0000:  6c00 0000 00ae 11ff fe80 0000 0000 0000  l...............
        0x0010:  a2f3 e4ff fe81 fe30 fe80 0000 0000 0000  .......0........
        0x0020:  0642 1aff fee4 d11d 0223 0222 00ae 0c89  .B.......#."....
        0x0030:  0721 0130 0002 000a 0003 0001 10e8 7872  .!.0..........xr
        0x0040:  6f51 0001 000a 0003 0001 0442 1ae4 d11d  oQ.........B....
        0x0050:  0003 0031 0000 0006 0000 0000 0000 0000  ...1............
        0x0060:  000d 0021 0002 4e6f 2061 6464 7265 7373  ...!..No.address
        0x0070:  6573 2068 6176 6520 6265 656e 2061 7373  es.have.been.ass
        0x0080:  6967 6e65 6400 1900 2900 0000 0100 0007  igned...).......
        0x0090:  0800 000b 4000 1a00 1900 000e 1000 0151  ....@..........Q
        0x00a0:  8040 2a01 05a8 030e 0995 0000 0000 0000  .@*.............
        0x00b0:  0000 0017 0020 2a01 05a8 0000 0000 0000  ......*.........
        0x00c0:  0000 0006 0042 2a01 05a8 0000 0000 0000  .....B*.........
        0x00d0:  0000 0006 0043                           .....C
00:11:55.382296 IP6 (flowlabel 0x72bfd, hlim 1, next-header UDP (17) payload length: 99) fe80::642:1aff:fee4:d11d.546 > ff02::1:2.547: [bad udp cksum 0xef3e -> 0xf67d!] dhcp6 solicit (xid=bc2ff9 (elapsed-time 0) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list SNTP-servers NTP-server opt_67 opt_82) (client-ID hwaddr type 1 xxxxxxxxxxxx) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:6 T1:0 T2:0) (IA_PD IAID:1 T1:0 T2:0))
        0x0000:  6007 2bfd 0063 1101 fe80 0000 0000 0000  `.+..c..........
        0x0010:  0642 1aff fee4 d11d ff02 0000 0000 0000  .B..............
        0x0020:  0000 0000 0001 0002 0222 0223 0063 ef3e  .........".#.c.>
        0x0030:  01bc 2ff9 0008 0002 0000 0006 0010 0015  ../.............
        0x0040:  0016 0017 0018 001f 0038 0043 0052 0001  .........8.C.R..
        0x0050:  000a 0003 0001 0442 1ae4 d11d 0014 0000  .......B........
        0x0060:  0027 0007 0004 4173 7573 0000 0300 0c00  .'....Asus......
        0x0070:  0000 0600 0000 0000 0000 0000 1900 0c00  ................
        0x0080:  0000 0100 0000 0000 0000 00              ...........
00:11:55.404664 IP6 (class 0xc0, hlim 255, next-header UDP (17) payload length: 165) fe80::a2f3:e4ff:fe81:fe30.547 > fe80::642:1aff:fee4:d11d.546: [udp sum ok] dhcp6 advertise (xid=bc2ff9 (server-ID hwaddr type 1 mac_1) (client-ID hwaddr type 1 xxxxxxxxxxxx) (IA_NA IAID:6 T1:300 T2:400 (IA_ADDR xaab-xbb8-30e-1982--1.v6.ispnamemasked.com pltime:600 vltime:600)) (IA_PD IAID:1 T1:1800 T2:2880 (IA_PD-prefix xaab-xbb8-x99e-xx--.v6.ispnamemasked.com/64 pltime:3600 vltime:86400)) (DNS-server xaab-xbb8--6-42.v6.ispnamemasked.com xaab-xbb8--6-43.v6.ispnamemasked.com))
        0x0000:  6c00 0000 00a5 11ff fe80 0000 0000 0000  l...............
        0x0010:  a2f3 e4ff fe81 fe30 fe80 0000 0000 0000  .......0........
        0x0020:  0642 1aff fee4 d11d 0223 0222 00a5 fece  .B.......#."....
        0x0030:  02bc 2ff9 0002 000a 0003 0001 10e8 7872  ../...........xr
        0x0040:  6f51 0001 000a 0003 0001 0442 1ae4 d11d  oQ.........B....
        0x0050:  0003 0028 0000 0006 0000 012c 0000 0190  ...(.......,....
        0x0060:  0005 0018 2a01 05a8 030e 1982 0000 0000  ....*...........
        0x0070:  0000 0001 0000 0258 0000 0258 0019 0029  .......X...X...)
        0x0080:  0000 0001 0000 0708 0000 0b40 001a 0019  ...........@....
        0x0090:  0000 0e10 0001 5180 402a 0105 a803 0e09  ......Q.@*......
        0x00a0:  9500 0000 0000 0000 0000 1700 202a 0105  .............*..
        0x00b0:  a800 0000 0000 0000 0000 0600 422a 0105  ............B*..
        0x00c0:  a800 0000 0000 0000 0000 0600 43         ............C
00:11:57.317640 IP6 (flowlabel 0x72bfd, hlim 1, next-header UDP (17) payload length: 168) fe80::642:1aff:fee4:d11d.546 > ff02::1:2.547: [bad udp cksum 0xef83 -> 0x24ec!] dhcp6 request (xid=8ec589 (elapsed-time 0) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list SNTP-servers NTP-server opt_67) (client-ID hwaddr type 1 xxxxxxxxxxxx) (server-ID hwaddr type 1 mac_1) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:6 T1:0 T2:0 (IA_ADDR xaab-xbb8-30e-1982--1.v6.ispnamemasked.com pltime:600 vltime:600)) (IA_PD IAID:1 T1:0 T2:0 (IA_PD-prefix xaab-xbb8-x99e-xx--.v6.ispnamemasked.com/64 pltime:3600 vltime:86400)))
        0x0000:  6007 2bfd 00a8 1101 fe80 0000 0000 0000  `.+.............
        0x0010:  0642 1aff fee4 d11d ff02 0000 0000 0000  .B..............
        0x0020:  0000 0000 0001 0002 0222 0223 00a8 ef83  .........".#....
        0x0030:  038e c589 0008 0002 0000 0006 000e 0015  ................
        0x0040:  0016 0017 0018 001f 0038 0043 0001 000a  .........8.C....
        0x0050:  0003 0001 0442 1ae4 d11d 0002 000a 0003  .....B..........
        0x0060:  0001 10e8 7872 6f51 0014 0000 0027 0007  ....xroQ.....'..
        0x0070:  0004 4173 7573 0000 0300 2800 0000 0600  ..Asus....(.....
        0x0080:  0000 0000 0000 0000 0500 182a 0105 a803  ...........*....
        0x0090:  0e19 8200 0000 0000 0000 0100 0002 5800  ..............X.
        0x00a0:  0002 5800 1900 2900 0000 0100 0000 0000  ..X...).........
        0x00b0:  0000 0000 1a00 1900 000e 1000 0151 8040  .............Q.@
        0x00c0:  2a01 05a8 030e 0995 0000 0000 0000 0000  *...............
00:11:57.344672 IP6 (class 0xc0, hlim 255, next-header UDP (17) payload length: 174) fe80::a2f3:e4ff:fe81:fe30.547 > fe80::642:1aff:fee4:d11d.546: [udp sum ok] dhcp6 reply (xid=8ec589 (server-ID hwaddr type 1 mac_1) (client-ID hwaddr type 1 xxxxxxxxxxxx) (IA_NA IAID:6 T1:0 T2:0 (status-code NoAddrsAvail)) (IA_PD IAID:1 T1:1800 T2:2880 (IA_PD-prefix xaab-xbb8-x99e-xx--.v6.ispnamemasked.com/64 pltime:3600 vltime:86400)) (DNS-server xaab-xbb8--6-42.v6.ispnamemasked.com xaab-xbb8--6-43.v6.ispnamemasked.com))
        0x0000:  6c00 0000 00ae 11ff fe80 0000 0000 0000  l...............
        0x0010:  a2f3 e4ff fe81 fe30 fe80 0000 0000 0000  .......0........
        0x0020:  0642 1aff fee4 d11d 0223 0222 00ae 47c2  .B.......#."..G.
        0x0030:  078e c589 0002 000a 0003 0001 10e8 7872  ..............xr
        0x0040:  6f51 0001 000a 0003 0001 0442 1ae4 d11d  oQ.........B....
        0x0050:  0003 0031 0000 0006 0000 0000 0000 0000  ...1............
        0x0060:  000d 0021 0002 4e6f 2061 6464 7265 7373  ...!..No.address
        0x0070:  6573 2068 6176 6520 6265 656e 2061 7373  es.have.been.ass
        0x0080:  6967 6e65 6400 1900 2900 0000 0100 0007  igned...).......
        0x0090:  0800 000b 4000 1a00 1900 000e 1000 0151  ....@..........Q
        0x00a0:  8040 2a01 05a8 030e 0995 0000 0000 0000  .@*.............
        0x00b0:  0000 0017 0020 2a01 05a8 0000 0000 0000  ......*.........
        0x00c0:  0000 0006 0042 2a01 05a8 0000 0000 0000  .....B*.........
        0x00d0:  0000 0006 0043                           .....C
00:11:57.717117 IP6 (flowlabel 0x72bfd, hlim 1, next-header UDP (17) payload length: 99) fe80::642:1aff:fee4:d11d.546 > ff02::1:2.547: [bad udp cksum 0xef3e -> 0x37e4!] dhcp6 solicit (xid=38ef16 (elapsed-time 0) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list SNTP-servers NTP-server opt_67 opt_82) (client-ID hwaddr type 1 xxxxxxxxxxxx) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:6 T1:0 T2:0) (IA_PD IAID:1 T1:0 T2:0))
        0x0000:  6007 2bfd 0063 1101 fe80 0000 0000 0000  `.+..c..........
        0x0010:  0642 1aff fee4 d11d ff02 0000 0000 0000  .B..............
        0x0020:  0000 0000 0001 0002 0222 0223 0063 ef3e  .........".#.c.>
        0x0030:  0138 ef16 0008 0002 0000 0006 0010 0015  .8..............
        0x0040:  0016 0017 0018 001f 0038 0043 0052 0001  .........8.C.R..
        0x0050:  000a 0003 0001 0442 1ae4 d11d 0014 0000  .......B........
        0x0060:  0027 0007 0004 4173 7573 0000 0300 0c00  .'....Asus......
        0x0070:  0000 0600 0000 0000 0000 0000 1900 0c00  ................
        0x0080:  0000 0100 0000 0000 0000 00              ...........
00:11:57.744649 IP6 (class 0xc0, hlim 255, next-header UDP (17) payload length: 165) fe80::a2f3:e4ff:fe81:fe30.547 > fe80::642:1aff:fee4:d11d.546: [udp sum ok] dhcp6 advertise (xid=38ef16 (server-ID hwaddr type 1 mac_1) (client-ID hwaddr type 1 xxxxxxxxxxxx) (IA_NA IAID:6 T1:300 T2:400 (IA_ADDR xaab-xbb8-30e-1982--1.v6.ispnamemasked.com pltime:600 vltime:600)) (IA_PD IAID:1 T1:1800 T2:2880 (IA_PD-prefix xaab-xbb8-x99e-xx--.v6.ispnamemasked.com/64 pltime:3600 vltime:86400)) (DNS-server xaab-xbb8--6-42.v6.ispnamemasked.com xaab-xbb8--6-43.v6.ispnamemasked.com))
        0x0000:  6c00 0000 00a5 11ff fe80 0000 0000 0000  l...............
        0x0010:  a2f3 e4ff fe81 fe30 fe80 0000 0000 0000  .......0........
        0x0020:  0642 1aff fee4 d11d 0223 0222 00a5 4035  .B.......#."..@5
        0x0030:  0238 ef16 0002 000a 0003 0001 10e8 7872  .8............xr
        0x0040:  6f51 0001 000a 0003 0001 0442 1ae4 d11d  oQ.........B....
        0x0050:  0003 0028 0000 0006 0000 012c 0000 0190  ...(.......,....
        0x0060:  0005 0018 2a01 05a8 030e 1982 0000 0000  ....*...........
        0x0070:  0000 0001 0000 0258 0000 0258 0019 0029  .......X...X...)
        0x0080:  0000 0001 0000 0708 0000 0b40 001a 0019  ...........@....
        0x0090:  0000 0e10 0001 5180 402a 0105 a803 0e09  ......Q.@*......
        0x00a0:  9500 0000 0000 0000 0000 1700 202a 0105  .............*..
        0x00b0:  a800 0000 0000 0000 0000 0600 422a 0105  ............B*..
        0x00c0:  a800 0000 0000 0000 0000 0600 43         ............C
00:11:58.874605 IP6 (flowlabel 0x72bfd, hlim 1, next-header UDP (17) payload length: 168) fe80::642:1aff:fee4:d11d.546 > ff02::1:2.547: [bad udp cksum 0xef83 -> 0xdc5f!] dhcp6 request (xid=2a0e7a (elapsed-time 0) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list SNTP-servers NTP-server opt_67) (client-ID hwaddr type 1 xxxxxxxxxxxx) (server-ID hwaddr type 1 mac_1) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:6 T1:0 T2:0 (IA_ADDR xaab-xbb8-30e-1982--1.v6.ispnamemasked.com pltime:600 vltime:600)) (IA_PD IAID:1 T1:0 T2:0 (IA_PD-prefix xaab-xbb8-x99e-xx--.v6.ispnamemasked.com/64 pltime:3600 vltime:86400)))
        0x0000:  6007 2bfd 00a8 1101 fe80 0000 0000 0000  `.+.............
        0x0010:  0642 1aff fee4 d11d ff02 0000 0000 0000  .B..............
        0x0020:  0000 0000 0001 0002 0222 0223 00a8 ef83  .........".#....
        0x0030:  032a 0e7a 0008 0002 0000 0006 000e 0015  .*.z............
        0x0040:  0016 0017 0018 001f 0038 0043 0001 000a  .........8.C....
        0x0050:  0003 0001 0442 1ae4 d11d 0002 000a 0003  .....B..........
        0x0060:  0001 10e8 7872 6f51 0014 0000 0027 0007  ....xroQ.....'..
        0x0070:  0004 4173 7573 0000 0300 2800 0000 0600  ..Asus....(.....
        0x0080:  0000 0000 0000 0000 0500 182a 0105 a803  ...........*....
        0x0090:  0e19 8200 0000 0000 0000 0100 0002 5800  ..............X.
        0x00a0:  0002 5800 1900 2900 0000 0100 0000 0000  ..X...).........
        0x00b0:  0000 0000 1a00 1900 000e 1000 0151 8040  .............Q.@
        0x00c0:  2a01 05a8 030e 0995 0000 0000 0000 0000  *...............
00:11:58.908367 IP6 (class 0xc0, hlim 255, next-header UDP (17) payload length: 174) fe80::a2f3:e4ff:fe81:fe30.547 > fe80::642:1aff:fee4:d11d.546: [udp sum ok] dhcp6 reply (xid=2a0e7a (server-ID hwaddr type 1 mac_1) (client-ID hwaddr type 1 xxxxxxxxxxxx) (IA_NA IAID:6 T1:0 T2:0 (status-code NoAddrsAvail)) (IA_PD IAID:1 T1:1800 T2:2880 (IA_PD-prefix xaab-xbb8-x99e-xx--.v6.ispnamemasked.com/64 pltime:3600 vltime:86400)) (DNS-server xaab-xbb8--6-42.v6.ispnamemasked.com xaab-xbb8--6-43.v6.ispnamemasked.com))
        0x0000:  6c00 0000 00ae 11ff fe80 0000 0000 0000  l...............
        0x0010:  a2f3 e4ff fe81 fe30 fe80 0000 0000 0000  .......0........
        0x0020:  0642 1aff fee4 d11d 0223 0222 00ae ff35  .B.......#."...5
        0x0030:  072a 0e7a 0002 000a 0003 0001 10e8 7872  .*.z..........xr
        0x0040:  6f51 0001 000a 0003 0001 0442 1ae4 d11d  oQ.........B....
        0x0050:  0003 0031 0000 0006 0000 0000 0000 0000  ...1............
        0x0060:  000d 0021 0002 4e6f 2061 6464 7265 7373  ...!..No.address
        0x0070:  6573 2068 6176 6520 6265 656e 2061 7373  es.have.been.ass
        0x0080:  6967 6e65 6400 1900 2900 0000 0100 0007  igned...).......
        0x0090:  0800 000b 4000 1a00 1900 000e 1000 0151  ....@..........Q
        0x00a0:  8040 2a01 05a8 030e 0995 0000 0000 0000  .@*.............
        0x00b0:  0000 0017 0020 2a01 05a8 0000 0000 0000  ......*.........
        0x00c0:  0000 0006 0042 2a01 05a8 0000 0000 0000  .....B*.........
        0x00d0:  0000 0006 0043                           .....C
00:11:58.967874 IP6 (flowlabel 0x72bfd, hlim 1, next-header UDP (17) payload length: 99) fe80::642:1aff:fee4:d11d.546 > ff02::1:2.547: [bad udp cksum 0xef3e -> 0x57ba!] dhcp6 solicit (xid=a1ced7 (elapsed-time 0) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list SNTP-servers NTP-server opt_67 opt_82) (client-ID hwaddr type 1 xxxxxxxxxxxx) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:6 T1:0 T2:0) (IA_PD IAID:1 T1:0 T2:0))
        0x0000:  6007 2bfd 0063 1101 fe80 0000 0000 0000  `.+..c..........
        0x0010:  0642 1aff fee4 d11d ff02 0000 0000 0000  .B..............
        0x0020:  0000 0000 0001 0002 0222 0223 0063 ef3e  .........".#.c.>
        0x0030:  01a1 ced7 0008 0002 0000 0006 0010 0015  ................
        0x0040:  0016 0017 0018 001f 0038 0043 0052 0001  .........8.C.R..
        0x0050:  000a 0003 0001 0442 1ae4 d11d 0014 0000  .......B........
        0x0060:  0027 0007 0004 4173 7573 0000 0300 0c00  .'....Asus......
        0x0070:  0000 0600 0000 0000 0000 0000 1900 0c00  ................
        0x0080:  0000 0100 0000 0000 0000 00              ...........
00:11:59.004627 IP6 (class 0xc0, hlim 255, next-header UDP (17) payload length: 165) fe80::a2f3:e4ff:fe81:fe30.547 > fe80::642:1aff:fee4:d11d.546: [udp sum ok] dhcp6 advertise (xid=a1ced7 (server-ID hwaddr type 1 mac_1) (client-ID hwaddr type 1 xxxxxxxxxxxx) (IA_NA IAID:6 T1:300 T2:400 (IA_ADDR xaab-xbb8-30e-1982--1.v6.ispnamemasked.com pltime:600 vltime:600)) (IA_PD IAID:1 T1:1800 T2:2880 (IA_PD-prefix xaab-xbb8-x99e-xx--.v6.ispnamemasked.com/64 pltime:3600 vltime:86400)) (DNS-server xaab-xbb8--6-42.v6.ispnamemasked.com xaab-xbb8--6-43.v6.ispnamemasked.com))
        0x0000:  6c00 0000 00a5 11ff fe80 0000 0000 0000  l...............
        0x0010:  a2f3 e4ff fe81 fe30 fe80 0000 0000 0000  .......0........
        0x0020:  0642 1aff fee4 d11d 0223 0222 00a5 600b  .B.......#."..`.
        0x0030:  02a1 ced7 0002 000a 0003 0001 10e8 7872  ..............xr
        0x0040:  6f51 0001 000a 0003 0001 0442 1ae4 d11d  oQ.........B....
        0x0050:  0003 0028 0000 0006 0000 012c 0000 0190  ...(.......,....
        0x0060:  0005 0018 2a01 05a8 030e 1982 0000 0000  ....*...........
        0x0070:  0000 0001 0000 0258 0000 0258 0019 0029  .......X...X...)
        0x0080:  0000 0001 0000 0708 0000 0b40 001a 0019  ...........@....
        0x0090:  0000 0e10 0001 5180 402a 0105 a803 0e09  ......Q.@*......
        0x00a0:  9500 0000 0000 0000 0000 1700 202a 0105  .............*..
        0x00b0:  a800 0000 0000 0000 0000 0600 422a 0105  ............B*..
        0x00c0:  a800 0000 0000 0000 0000 0600 43         ............C
00:12:00.180699 IP6 (flowlabel 0x72bfd, hlim 1, next-header UDP (17) payload length: 168) fe80::642:1aff:fee4:d11d.546 > ff02::1:2.547: [bad udp cksum 0xef83 -> 0x3584!] dhcp6 request (xid=d2b4ad (elapsed-time 0) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list SNTP-servers NTP-server opt_67) (client-ID hwaddr type 1 xxxxxxxxxxxx) (server-ID hwaddr type 1 mac_1) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:6 T1:0 T2:0 (IA_ADDR xaab-xbb8-30e-1982--1.v6.ispnamemasked.com pltime:600 vltime:600)) (IA_PD IAID:1 T1:0 T2:0 (IA_PD-prefix xaab-xbb8-x99e-xx--.v6.ispnamemasked.com/64 pltime:3600 vltime:86400)))
        0x0000:  6007 2bfd 00a8 1101 fe80 0000 0000 0000  `.+.............
        0x0010:  0642 1aff fee4 d11d ff02 0000 0000 0000  .B..............
        0x0020:  0000 0000 0001 0002 0222 0223 00a8 ef83  .........".#....
        0x0030:  03d2 b4ad 0008 0002 0000 0006 000e 0015  ................
        0x0040:  0016 0017 0018 001f 0038 0043 0001 000a  .........8.C....
        0x0050:  0003 0001 0442 1ae4 d11d 0002 000a 0003  .....B..........
        0x0060:  0001 10e8 7872 6f51 0014 0000 0027 0007  ....xroQ.....'..
        0x0070:  0004 4173 7573 0000 0300 2800 0000 0600  ..Asus....(.....
        0x0080:  0000 0000 0000 0000 0500 182a 0105 a803  ...........*....
        0x0090:  0e19 8200 0000 0000 0000 0100 0002 5800  ..............X.
        0x00a0:  0002 5800 1900 2900 0000 0100 0000 0000  ..X...).........
        0x00b0:  0000 0000 1a00 1900 000e 1000 0151 8040  .............Q.@
        0x00c0:  2a01 05a8 030e 0995 0000 0000 0000 0000  *...............
00:12:00.204652 IP6 (class 0xc0, hlim 255, next-header UDP (17) payload length: 174) fe80::a2f3:e4ff:fe81:fe30.547 > fe80::642:1aff:fee4:d11d.546: [udp sum ok] dhcp6 reply (xid=d2b4ad (server-ID hwaddr type 1 mac_1) (client-ID hwaddr type 1 xxxxxxxxxxxx) (IA_NA IAID:6 T1:0 T2:0 (status-code NoAddrsAvail)) (IA_PD IAID:1 T1:1800 T2:2880 (IA_PD-prefix xaab-xbb8-x99e-xx--.v6.ispnamemasked.com/64 pltime:3600 vltime:86400)) (DNS-server xaab-xbb8--6-42.v6.ispnamemasked.com xaab-xbb8--6-43.v6.ispnamemasked.com))
        0x0000:  6c00 0000 00ae 11ff fe80 0000 0000 0000  l...............
        0x0010:  a2f3 e4ff fe81 fe30 fe80 0000 0000 0000  .......0........
        0x0020:  0642 1aff fee4 d11d 0223 0222 00ae 585a  .B.......#."..XZ
        0x0030:  07d2 b4ad 0002 000a 0003 0001 10e8 7872  ..............xr
        0x0040:  6f51 0001 000a 0003 0001 0442 1ae4 d11d  oQ.........B....
        0x0050:  0003 0031 0000 0006 0000 0000 0000 0000  ...1............
        0x0060:  000d 0021 0002 4e6f 2061 6464 7265 7373  ...!..No.address
        0x0070:  6573 2068 6176 6520 6265 656e 2061 7373  es.have.been.ass
        0x0080:  6967 6e65 6400 1900 2900 0000 0100 0007  igned...).......
        0x0090:  0800 000b 4000 1a00 1900 000e 1000 0151  ....@..........Q
        0x00a0:  8040 2a01 05a8 030e 0995 0000 0000 0000  .@*.............
        0x00b0:  0000 0017 0020 2a01 05a8 0000 0000 0000  ......*.........
        0x00c0:  0000 0006 0042 2a01 05a8 0000 0000 0000  .....B*.........
        0x00d0:  0000 0006 0043                           .....C
00:12:00.382155 IP6 (flowlabel 0x72bfd, hlim 1, next-header UDP (17) payload length: 99) fe80::642:1aff:fee4:d11d.546 > ff02::1:2.547: [bad udp cksum 0xef3e -> 0x04f0!] dhcp6 solicit (xid=5621ed (elapsed-time 0) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list SNTP-servers NTP-server opt_67 opt_82) (client-ID hwaddr type 1 xxxxxxxxxxxx) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:6 T1:0 T2:0) (IA_PD IAID:1 T1:0 T2:0))
        0x0000:  6007 2bfd 0063 1101 fe80 0000 0000 0000  `.+..c..........
        0x0010:  0642 1aff fee4 d11d ff02 0000 0000 0000  .B..............
        0x0020:  0000 0000 0001 0002 0222 0223 0063 ef3e  .........".#.c.>
        0x0030:  0156 21ed 0008 0002 0000 0006 0010 0015  .V!.............
        0x0040:  0016 0017 0018 001f 0038 0043 0052 0001  .........8.C.R..
        0x0050:  000a 0003 0001 0442 1ae4 d11d 0014 0000  .......B........
        0x0060:  0027 0007 0004 4173 7573 0000 0300 0c00  .'....Asus......
        0x0070:  0000 0600 0000 0000 0000 0000 1900 0c00  ................
        0x0080:  0000 0100 0000 0000 0000 00              ...........
00:12:00.404638 IP6 (class 0xc0, hlim 255, next-header UDP (17) payload length: 165) fe80::a2f3:e4ff:fe81:fe30.547 > fe80::642:1aff:fee4:d11d.546: [udp sum ok] dhcp6 advertise (xid=5621ed (server-ID hwaddr type 1 mac_1) (client-ID hwaddr type 1 xxxxxxxxxxxx) (IA_NA IAID:6 T1:300 T2:400 (IA_ADDR xaab-xbb8-30e-1982--1.v6.ispnamemasked.com pltime:600 vltime:600)) (IA_PD IAID:1 T1:1800 T2:2880 (IA_PD-prefix xaab-xbb8-x99e-xx--.v6.ispnamemasked.com/64 pltime:3600 vltime:86400)) (DNS-server xaab-xbb8--6-42.v6.ispnamemasked.com xaab-xbb8--6-43.v6.ispnamemasked.com))
        0x0000:  6c00 0000 00a5 11ff fe80 0000 0000 0000  l...............
        0x0010:  a2f3 e4ff fe81 fe30 fe80 0000 0000 0000  .......0........
        0x0020:  0642 1aff fee4 d11d 0223 0222 00a5 0d41  .B.......#."...A
        0x0030:  0256 21ed 0002 000a 0003 0001 10e8 7872  .V!...........xr
        0x0040:  6f51 0001 000a 0003 0001 0442 1ae4 d11d  oQ.........B....
        0x0050:  0003 0028 0000 0006 0000 012c 0000 0190  ...(.......,....
        0x0060:  0005 0018 2a01 05a8 030e 1982 0000 0000  ....*...........
        0x0070:  0000 0001 0000 0258 0000 0258 0019 0029  .......X...X...)
        0x0080:  0000 0001 0000 0708 0000 0b40 001a 0019  ...........@....
        0x0090:  0000 0e10 0001 5180 402a 0105 a803 0e09  ......Q.@*......
        0x00a0:  9500 0000 0000 0000 0000 1700 202a 0105  .............*..
        0x00b0:  a800 0000 0000 0000 0000 0600 422a 0105  ............B*..
        0x00c0:  a800 0000 0000 0000 0000 0600 43         ............C
00:12:02.283701 IP6 (flowlabel 0x72bfd, hlim 1, next-header UDP (17) payload length: 168) fe80::642:1aff:fee4:d11d.546 > ff02::1:2.547: [bad udp cksum 0xef83 -> 0x0592!] dhcp6 request (xid=69e508 (elapsed-time 0) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list SNTP-servers NTP-server opt_67) (client-ID hwaddr type 1 xxxxxxxxxxxx) (server-ID hwaddr type 1 mac_1) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:6 T1:0 T2:0 (IA_ADDR xaab-xbb8-30e-1982--1.v6.ispnamemasked.com pltime:600 vltime:600)) (IA_PD IAID:1 T1:0 T2:0 (IA_PD-prefix xaab-xbb8-x99e-xx--.v6.ispnamemasked.com/64 pltime:3600 vltime:86400)))
        0x0000:  6007 2bfd 00a8 1101 fe80 0000 0000 0000  `.+.............
        0x0010:  0642 1aff fee4 d11d ff02 0000 0000 0000  .B..............
        0x0020:  0000 0000 0001 0002 0222 0223 00a8 ef83  .........".#....
        0x0030:  0369 e508 0008 0002 0000 0006 000e 0015  .i..............
        0x0040:  0016 0017 0018 001f 0038 0043 0001 000a  .........8.C....
        0x0050:  0003 0001 0442 1ae4 d11d 0002 000a 0003  .....B..........
        0x0060:  0001 10e8 7872 6f51 0014 0000 0027 0007  ....xroQ.....'..
        0x0070:  0004 4173 7573 0000 0300 2800 0000 0600  ..Asus....(.....
        0x0080:  0000 0000 0000 0000 0500 182a 0105 a803  ...........*....
        0x0090:  0e19 8200 0000 0000 0000 0100 0002 5800  ..............X.
        0x00a0:  0002 5800 1900 2900 0000 0100 0000 0000  ..X...).........
        0x00b0:  0000 0000 1a00 1900 000e 1000 0151 8040  .............Q.@
        0x00c0:  2a01 05a8 030e 0995 0000 0000 0000 0000  *...............
00:12:02.304613 IP6 (class 0xc0, hlim 255, next-header UDP (17) payload length: 174) fe80::a2f3:e4ff:fe81:fe30.547 > fe80::642:1aff:fee4:d11d.546: [udp sum ok] dhcp6 reply (xid=69e508 (server-ID hwaddr type 1 mac_1) (client-ID hwaddr type 1 xxxxxxxxxxxx) (IA_NA IAID:6 T1:0 T2:0 (status-code NoAddrsAvail)) (IA_PD IAID:1 T1:1800 T2:2880 (IA_PD-prefix xaab-xbb8-x99e-xx--.v6.ispnamemasked.com/64 pltime:3600 vltime:86400)) (DNS-server xaab-xbb8--6-42.v6.ispnamemasked.com xaab-xbb8--6-43.v6.ispnamemasked.com))
        0x0000:  6c00 0000 00ae 11ff fe80 0000 0000 0000  l...............
        0x0010:  a2f3 e4ff fe81 fe30 fe80 0000 0000 0000  .......0........
        0x0020:  0642 1aff fee4 d11d 0223 0222 00ae 2868  .B.......#."..(h
        0x0030:  0769 e508 0002 000a 0003 0001 10e8 7872  .i............xr
        0x0040:  6f51 0001 000a 0003 0001 0442 1ae4 d11d  oQ.........B....
        0x0050:  0003 0031 0000 0006 0000 0000 0000 0000  ...1............
        0x0060:  000d 0021 0002 4e6f 2061 6464 7265 7373  ...!..No.address
        0x0070:  6573 2068 6176 6520 6265 656e 2061 7373  es.have.been.ass
        0x0080:  6967 6e65 6400 1900 2900 0000 0100 0007  igned...).......
        0x0090:  0800 000b 4000 1a00 1900 000e 1000 0151  ....@..........Q
        0x00a0:  8040 2a01 05a8 030e 0995 0000 0000 0000  .@*.............
        0x00b0:  0000 0017 0020 2a01 05a8 0000 0000 0000  ......*.........
        0x00c0:  0000 0006 0042 2a01 05a8 0000 0000 0000  .....B*.........
        0x00d0:  0000 0006 0043                           .....C
00:12:03.184062 IP6 (flowlabel 0x72bfd, hlim 1, next-header UDP (17) payload length: 99) fe80::642:1aff:fee4:d11d.546 > ff02::1:2.547: [bad udp cksum 0xef3e -> 0x8af9!] dhcp6 solicit (xid=d9c2c (elapsed-time 0) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list SNTP-servers NTP-server opt_67 opt_82) (client-ID hwaddr type 1 xxxxxxxxxxxx) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:6 T1:0 T2:0) (IA_PD IAID:1 T1:0 T2:0))
        0x0000:  6007 2bfd 0063 1101 fe80 0000 0000 0000  `.+..c..........
        0x0010:  0642 1aff fee4 d11d ff02 0000 0000 0000  .B..............
        0x0020:  0000 0000 0001 0002 0222 0223 0063 ef3e  .........".#.c.>
        0x0030:  010d 9c2c 0008 0002 0000 0006 0010 0015  ...,............
        0x0040:  0016 0017 0018 001f 0038 0043 0052 0001  .........8.C.R..
        0x0050:  000a 0003 0001 0442 1ae4 d11d 0014 0000  .......B........
        0x0060:  0027 0007 0004 4173 7573 0000 0300 0c00  .'....Asus......
        0x0070:  0000 0600 0000 0000 0000 0000 1900 0c00  ................
        0x0080:  0000 0100 0000 0000 0000 00              ...........
^C
77 packets captured
77 packets received by filter
0 packets dropped by kernel

Is this enough?

systemcrash · October 28, 2025, 9:47pm

You get valid replies. But why do you have a wan6 prefix on the wan6 interface?

?

First remove that.

Then perhaps try without this after.

sppmaster · October 28, 2025, 9:53pm

I removed both options and rebooted the router but I still get

odhcp6c[23012]: Server returned IA_PD status 'No Address Available (No addresses have been assigned)'

systemcrash · October 28, 2025, 10:02pm

Recommend you re-run the tcpdump command and show me all the output which includes when you press the restart button on wan6. ( update the existing post )

You only need to capture about 30 seconds.

Also while you’re there, run ip ad and see what ipv6 you get on the wan6

sppmaster · October 28, 2025, 10:21pm

I updated my post above but I don't get any address on wan6. It's missing from the list when I run ip ad.

_bernd · October 28, 2025, 10:26pm

I would also test an explicit 56.
You may have to "cool down" after power off the router and modem and wait for like 10 to 20 min. Depending on the provider this sometimes helps to get a clean renewal.

I also second that you remove the class and the norelease option.

systemcrash · October 28, 2025, 10:31pm

I see solicit, advertise, request with an IA_NA IAID:6 and IA_PD IAID:1. Your ITSP responds NoAddrsAvail:

00:11:54.944725 IP6 (class 0xc0, hlim 255, next-header UDP (17) payload length: 174) fe80::a2f3:e4ff:fe81:fe30.547 > fe80::642:1aff:fee4:d11d.546: [udp sum ok] dhcp6 reply (xid=210130 (server-ID hwaddr type 1 10e878726f51) (client-ID hwaddr type 1 04421ae4d11d) (IA_NA IAID:6 T1:0 T2:0 (status-code NoAddrsAvail)) (IA_PD IAID:1 T1:1800 T2:2880 (IA_PD-prefix xaab-xbb8-x99e-xx--.v6.ispnamemasked.com/64 pltime:3600 vltime:86400)) (DNS-server xaab-xbb8--6-42.v6.ispnamemasked.com xaab-xbb8--6-43.v6.ispnamemasked.com))
        0x0000:  6c00 0000 00ae 11ff fe80 0000 0000 0000  l...............
        0x0010:  a2f3 e4ff fe81 fe30 fe80 0000 0000 0000  .......0........
        0x0020:  0642 1aff fee4 d11d 0223 0222 00ae 0c89  .B.......#."....
        0x0030:  0721 0130 0002 000a 0003 0001 10e8 7872  .!.0..........xr
        0x0040:  6f51 0001 000a 0003 0001 0442 1ae4 d11d  oQ.........B....
        0x0050:  0003 0031 0000 0006 0000 0000 0000 0000  ...1............
        0x0060:  000d 0021 0002 4e6f 2061 6464 7265 7373  ...!..No.address
        0x0070:  6573 2068 6176 6520 6265 656e 2061 7373  es.have.been.ass
        0x0080:  6967 6e65 6400 1900 2900 0000 0100 0007  igned...).......
        0x0090:  0800 000b 4000 1a00 1900 000e 1000 0151  ....@..........Q
        0x00a0:  8040 2a01 05a8 030e 0995 0000 0000 0000  .@*.............
        0x00b0:  0000 0017 0020 2a01 05a8 0000 0000 0000  ......*.........
        0x00c0:  0000 0006 0042 2a01 05a8 0000 0000 0000  .....B*.........
        0x00d0:  0000 0006 0043                           .....C

But you get the PD.

The IA_NA has short Pre/Val lifetimes: 600.

Your client requests it…

sppmaster · October 28, 2025, 10:33pm

My ISP only gives PD of /64.

Yea IPv6 worked for more than two years and now I get this. I rebooted the ISP ONT but still same issue.

systemcrash · October 28, 2025, 11:02pm

One guess at this stage is that your address is still ‘bound’ to the old DUID sent before upgrade. There were some changes to how DUIDs are handled in odhcp6c. So in the worst case, you might need to switch off the ONT and disconnect the router for 600 seconds for that IPv6.

The bit I don’t get yet is why you’re offered an address, client accepts and requests, but it’s rejected.

The exchange looks sane.

I run a bleeding edge odhcp6c including all the commits you have, so I figure the Nokia gear at your ITSP is playing daft.

sppmaster · October 28, 2025, 11:12pm

I flashed my two week older build and it immediately got IPv6.

systemcrash · October 28, 2025, 11:14pm

Could you repeat the capture process and include just the first several packets of solicit, advertise, request reponse?

sppmaster · October 28, 2025, 11:21pm

That's all it was able to capture.

tcpdump: listening on wan, link-type EN10MB (Ethernet), snapshot length 262144 bytes
01:17:25.280123 IP6 (flowlabel 0x3ff1e, hlim 1, next-header UDP (17) payload length: 164) fe80::642:1aff:fee4:d11d.546 > ff02::1:2.547: [bad udp cksum 0xef7f -> 0x735a!] dhcp6 release (xid=20b951 (elapsed-time 0) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list SNTP-servers NTP-server opt_67) (client-ID hwaddr type 1 xxxxxxxxxxxx) (server-ID hwaddr type 1 mac_1) (Client-FQDN) (IA_NA IAID:1 T1:0 T2:0 (IA_ADDR xaab-xbb8-x99e-1982--1.v6.ispnamemasked.com pltime:0 vltime:0)) (IA_PD IAID:1 T1:0 T2:0 (IA_PD-prefix xaab-xbb8-x99e-94d--.v6.ispnamemasked.com/64 pltime:0 vltime:0)))
        0x0000:  6003 ff1e 00a4 1101 fe80 0000 0000 0000  `...............
        0x0010:  0642 1aff fee4 d11d ff02 0000 0000 0000  .B..............
        0x0020:  0000 0000 0001 0002 0222 0223 00a4 ef7f  .........".#....
        0x0030:  0820 b951 0008 0002 0000 0006 000e 0015  ...Q............
        0x0040:  0016 0017 0018 001f 0038 0043 0001 000a  .........8.C....
        0x0050:  0003 0001 0442 1ae4 d11d 0002 000a 0003  .....B..........
        0x0060:  0001 10e8 7872 6f51 0027 0007 0004 4173  ....xroQ.'....As
        0x0070:  7573 0000 0300 2800 0000 0100 0000 0000  us....(.........
        0x0080:  0000 0000 0500 182a 0105 a803 0e19 8200  .......*........
        0x0090:  0000 0000 0000 0100 0000 0000 0000 0000  ................
        0x00a0:  1900 2900 0000 0100 0000 0000 0000 0000  ..).............
        0x00b0:  1a00 1900 0000 0000 0000 0040 2a01 05a8  ...........@*...
        0x00c0:  030e 094d 0000 0000 0000 0000            ...M........
01:17:25.315868 IP6 (class 0xc0, hlim 255, next-header UDP (17) payload length: 147) fe80::a2f3:e4ff:fe81:fe30.547 > fe80::642:1aff:fee4:d11d.546: [udp sum ok] dhcp6 reply (xid=20b951 (server-ID hwaddr type 1 mac_1) (client-ID hwaddr type 1 xxxxxxxxxxxx) (IA_NA IAID:1 T1:0 T2:0 (status-code Success)) (IA_PD IAID:1 T1:0 T2:0 (status-code Success)))
        0x0000:  6c00 0000 0093 11ff fe80 0000 0000 0000  l...............
        0x0010:  a2f3 e4ff fe81 fe30 fe80 0000 0000 0000  .......0........
        0x0020:  0642 1aff fee4 d11d 0223 0222 0093 e1c0  .B.......#."....
        0x0030:  0720 b951 0002 000a 0003 0001 10e8 7872  ...Q..........xr
        0x0040:  6f51 0001 000a 0003 0001 0442 1ae4 d11d  oQ.........B....
        0x0050:  0003 0032 0000 0001 0000 0000 0000 0000  ...2............
        0x0060:  000d 0022 0000 416c 6c20 6164 6472 6573  ..."..All.addres
        0x0070:  7365 7320 6861 7665 2062 6565 6e20 7265  ses.have.been.re
        0x0080:  6c65 6173 6564 0019 0031 0000 0001 0000  leased...1......
        0x0090:  0000 0000 0000 000d 0021 0000 416c 6c20  .........!..All.
        0x00a0:  7072 6566 6978 6573 2068 6176 6520 6265  prefixes.have.be
        0x00b0:  656e 2072 656c 6561 7365 64              en.released
01:17:25.559583 IP6 (flowlabel 0x3ff1e, hlim 1, next-header UDP (17) payload length: 99) fe80::642:1aff:fee4:d11d.546 > ff02::1:2.547: [bad udp cksum 0xef3e -> 0xf3ad!] dhcp6 solicit (xid=1d3868 (elapsed-time 0) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list SNTP-servers NTP-server opt_67 opt_82) (client-ID hwaddr type 1 xxxxxxxxxxxx) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:1 T1:0 T2:0) (IA_PD IAID:1 T1:0 T2:0))
        0x0000:  6003 ff1e 0063 1101 fe80 0000 0000 0000  `....c..........
        0x0010:  0642 1aff fee4 d11d ff02 0000 0000 0000  .B..............
        0x0020:  0000 0000 0001 0002 0222 0223 0063 ef3e  .........".#.c.>
        0x0030:  011d 3868 0008 0002 0000 0006 0010 0015  ..8h............
        0x0040:  0016 0017 0018 001f 0038 0043 0052 0001  .........8.C.R..
        0x0050:  000a 0003 0001 0442 1ae4 d11d 0014 0000  .......B........
        0x0060:  0027 0007 0004 4173 7573 0000 0300 0c00  .'....Asus......
        0x0070:  0000 0100 0000 0000 0000 0000 1900 0c00  ................
        0x0080:  0000 0100 0000 0000 0000 00              ...........
01:17:25.586823 IP6 (class 0xc0, hlim 255, next-header UDP (17) payload length: 165) fe80::a2f3:e4ff:fe81:fe30.547 > fe80::642:1aff:fee4:d11d.546: [udp sum ok] dhcp6 advertise (xid=1d3868 (server-ID hwaddr type 1 mac_1) (client-ID hwaddr type 1 xxxxxxxxxxxx) (IA_NA IAID:1 T1:300 T2:400 (IA_ADDR xaab-xbb8-x99e-1982--1.v6.ispnamemasked.com pltime:600 vltime:600)) (IA_PD IAID:1 T1:300 T2:400 (IA_PD-prefix xaab-xbb8-x99e-94d--.v6.ispnamemasked.com/64 pltime:600 vltime:600)) (DNS-server xaab-xbb8--6-42.v6.ispnamemasked.com xaab-xbb8--6-43.v6.ispnamemasked.com))
        0x0000:  6c00 0000 00a5 11ff fe80 0000 0000 0000  l...............
        0x0010:  a2f3 e4ff fe81 fe30 fe80 0000 0000 0000  .......0........
        0x0020:  0642 1aff fee4 d11d 0223 0222 00a5 a971  .B.......#."...q
        0x0030:  021d 3868 0002 000a 0003 0001 10e8 7872  ..8h..........xr
        0x0040:  6f51 0001 000a 0003 0001 0442 1ae4 d11d  oQ.........B....
        0x0050:  0003 0028 0000 0001 0000 012c 0000 0190  ...(.......,....
        0x0060:  0005 0018 2a01 05a8 030e 1982 0000 0000  ....*...........
        0x0070:  0000 0001 0000 0258 0000 0258 0019 0029  .......X...X...)
        0x0080:  0000 0001 0000 012c 0000 0190 001a 0019  .......,........
        0x0090:  0000 0258 0000 0258 402a 0105 a803 0e09  ...X...X@*......
        0x00a0:  4d00 0000 0000 0000 0000 1700 202a 0105  M............*..
        0x00b0:  a800 0000 0000 0000 0000 0600 422a 0105  ............B*..
        0x00c0:  a800 0000 0000 0000 0000 0600 43         ............C
01:17:25.587496 IP6 (class 0xc0, hlim 255, next-header UDP (17) payload length: 145) fe80::a2f3:e4ff:fe81:fe30.547 > fe80::642:1aff:fee4:d11d.546: [udp sum ok] dhcp6 advertise (xid=1d3868 (server-ID hwaddr type 1 mac_2) (client-ID hwaddr type 1 xxxxxxxxxxxx) (IA_NA IAID:1 T1:0 T2:0 (status-code NoAddrsAvail)) (IA_PD IAID:1 T1:0 T2:0 (status-code NoPrefixAvail)))
        0x0000:  6c00 0000 0091 11ff fe80 0000 0000 0000  l...............
        0x0010:  a2f3 e4ff fe81 fe30 fe80 0000 0000 0000  .......0........
        0x0020:  0642 1aff fee4 d11d 0223 0222 0091 2ab3  .B.......#."..*.
        0x0030:  021d 3868 0002 000a 0003 0001 0023 3e8a  ..8h.........#>.
        0x0040:  4650 0001 000a 0003 0001 0442 1ae4 d11d  FP.........B....
        0x0050:  0003 0031 0000 0001 0000 0000 0000 0000  ...1............
        0x0060:  000d 0021 0002 4e6f 2061 6464 7265 7373  ...!..No.address
        0x0070:  6573 2068 6176 6520 6265 656e 2061 7373  es.have.been.ass
        0x0080:  6967 6e65 6400 1900 3000 0000 0100 0000  igned...0.......
        0x0090:  0000 0000 0000 0d00 2000 064e 6f20 7072  ...........No.pr
        0x00a0:  6566 6978 6573 2068 6176 6520 6265 656e  efixes.have.been
        0x00b0:  2061 7373 6967 6e65 64                   .assigned
01:17:26.703164 IP6 (flowlabel 0x3ff1e, hlim 1, next-header UDP (17) payload length: 168) fe80::642:1aff:fee4:d11d.546 > ff02::1:2.547: [bad udp cksum 0xef83 -> 0xc2e7!] dhcp6 request (xid=70eb8 (elapsed-time 0) (option-request SIP-servers-domain SIP-servers-address DNS-server DNS-search-list SNTP-servers NTP-server opt_67) (client-ID hwaddr type 1 xxxxxxxxxxxx) (server-ID hwaddr type 1 mac_1) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:1 T1:0 T2:0 (IA_ADDR xaab-xbb8-x99e-1982--1.v6.ispnamemasked.com pltime:600 vltime:600)) (IA_PD IAID:1 T1:0 T2:0 (IA_PD-prefix xaab-xbb8-x99e-94d--.v6.ispnamemasked.com/64 pltime:600 vltime:600)))
        0x0000:  6003 ff1e 00a8 1101 fe80 0000 0000 0000  `...............
        0x0010:  0642 1aff fee4 d11d ff02 0000 0000 0000  .B..............
        0x0020:  0000 0000 0001 0002 0222 0223 00a8 ef83  .........".#....
        0x0030:  0307 0eb8 0008 0002 0000 0006 000e 0015  ................
        0x0040:  0016 0017 0018 001f 0038 0043 0001 000a  .........8.C....
        0x0050:  0003 0001 0442 1ae4 d11d 0002 000a 0003  .....B..........
        0x0060:  0001 10e8 7872 6f51 0014 0000 0027 0007  ....xroQ.....'..
        0x0070:  0004 4173 7573 0000 0300 2800 0000 0100  ..Asus....(.....
        0x0080:  0000 0000 0000 0000 0500 182a 0105 a803  ...........*....
        0x0090:  0e19 8200 0000 0000 0000 0100 0002 5800  ..............X.
        0x00a0:  0002 5800 1900 2900 0000 0100 0000 0000  ..X...).........
        0x00b0:  0000 0000 1a00 1900 0002 5800 0002 5840  ..........X...X@
        0x00c0:  2a01 05a8 030e 094d 0000 0000 0000 0000  *......M........
01:17:26.729843 IP6 (class 0xc0, hlim 255, next-header UDP (17) payload length: 165) fe80::a2f3:e4ff:fe81:fe30.547 > fe80::642:1aff:fee4:d11d.546: [udp sum ok] dhcp6 reply (xid=70eb8 (server-ID hwaddr type 1 mac_1) (client-ID hwaddr type 1 xxxxxxxxxxxx) (IA_NA IAID:1 T1:300 T2:400 (IA_ADDR xaab-xbb8-x99e-1982--1.v6.ispnamemasked.com pltime:600 vltime:600)) (IA_PD IAID:1 T1:300 T2:400 (IA_PD-prefix xaab-xbb8-x99e-94d--.v6.ispnamemasked.com/64 pltime:600 vltime:600)) (DNS-server xaab-xbb8--6-42.v6.ispnamemasked.com xaab-xbb8--6-43.v6.ispnamemasked.com))
        0x0000:  6c00 0000 00a5 11ff fe80 0000 0000 0000  l...............
        0x0010:  a2f3 e4ff fe81 fe30 fe80 0000 0000 0000  .......0........
        0x0020:  0642 1aff fee4 d11d 0223 0222 00a5 ce37  .B.......#."...7
        0x0030:  0707 0eb8 0002 000a 0003 0001 10e8 7872  ..............xr
        0x0040:  6f51 0001 000a 0003 0001 0442 1ae4 d11d  oQ.........B....
        0x0050:  0003 0028 0000 0001 0000 012c 0000 0190  ...(.......,....
        0x0060:  0005 0018 2a01 05a8 030e 1982 0000 0000  ....*...........
        0x0070:  0000 0001 0000 0258 0000 0258 0019 0029  .......X...X...)
        0x0080:  0000 0001 0000 012c 0000 0190 001a 0019  .......,........
        0x0090:  0000 0258 0000 0258 402a 0105 a803 0e09  ...X...X@*......
        0x00a0:  4d00 0000 0000 0000 0000 1700 202a 0105  M............*..
        0x00b0:  a800 0000 0000 0000 0000 0600 422a 0105  ............B*..
        0x00c0:  a800 0000 0000 0000 0000 0600 43         ............C
01:17:26.812447 IP6 (class 0xc0, hlim 255, next-header ICMPv6 (58) payload length: 24) fe80::a2f3:e4ff:fe81:fe30 > fe80::642:1aff:fee4:d11d: [icmp6 sum ok] ICMP6, router advertisement, length 24
        hop limit 64, Flags [managed], pref medium, router lifetime 4500s, reachable time 0ms, retrans timer 0ms
          source link-address option (1), length 8 (1): 00:00:5e:00:01:13
        0x0000:  6c00 0000 0018 3aff fe80 0000 0000 0000  l.....:.........
        0x0010:  a2f3 e4ff fe81 fe30 fe80 0000 0000 0000  .......0........
        0x0020:  0642 1aff fee4 d11d 8600 5498 4080 1194  .B........T.@...
        0x0030:  0000 0000 0000 0000 0101 0000 5e00 0113  ............^...
^C
8 packets captured
8 packets received by filter
0 packets dropped by kernel

systemcrash · October 28, 2025, 11:29pm

That’s nuts. You have two DHCPv6 servers clashing during advertise. The Nokia gear now gives you an IPv6, but the AlcatelLucent says Status Code: NoAddrsAvail (2).

The only appreciable difference I can identify is during the OK scenario:

IA_NA IAID:1

IA_PD IAID:1

During the problem scenario:

IA_NA IAID:6

IA_PD IAID:1

If you can build odhcp6c without commit e24ac1cf8c27116705f6abedd89be4d7533fc511 then I think we found the problem here.

sppmaster · October 28, 2025, 11:55pm

I cannot find that commit.

systemcrash · October 28, 2025, 11:58pm

It’s an odhcp6c commit, not openwrt commit. You’ll likely need to do:

scripts/update_git_source_package.sh ./package/network/services/odhcpd/Makefile 053e6c4b386348834e35e5fefc921fadc0e64025

Get update_git_source_package from https://raw.githubusercontent.com/openwrt/maintainer-tools/refs/heads/master/update_git_source_package.sh

Optionally run make menuconfig and choose odhcp6c as a module and do the usual make package/odhcp6c/compile to build just the odhcp6c so it’s easier to compare.

===

If it is that commit, I have a fix/workaround which goes something like:

on old working build, uncheck option option norelease '1'
perform upgrade to the build with the problem scenario

This way, the old odhcp6c sends a release of the old IPv6, before the new odhcp6c requests.

The problem I am looking at here is: https://www.rfc-editor.org/rfc/rfc8415#section-12


   The IAID uniquely identifies the IA and MUST be chosen to be unique
   among the IAIDs for that IA type on the client (e.g., an IA_NA with
   an IAID of 0 and an IA_PD with an IAID of 0 are each considered
   unique).  The IAID is chosen by the client.  *For any given use of an
   IA by the client, the IAID for that IA MUST be consistent across
   restarts of the DHCP client.*

The solution is otherwise to wait the 600 seconds until your lease expires at the ISP.

sppmaster · October 29, 2025, 6:19pm

I've waited a lot more than 600 seconds but it doesn't connect. I will have to find some spare time to compile and test what you suggested but I had some troubles bricking the router and it took some time to recover it.