daemon.warn odhcp6c[32628]: Server returned IA_PD status 'No Address Available (No addresses have been assigned)'
So I tried to manually start odhcp6c to get more information, and the following output was generated:
root@OpenWrt:~# odhcp6c -s /lib/netifd/dhcpv6.script -N try -e -P 0 -v pppoe-wan
odhcp6c[11609]: (re)starting transaction on pppoe-wan
Command failed: Not found
odhcp6c[11609]: Starting SOLICIT transaction (timeout 4294967295s, max rc 0)
odhcp6c[11609]: Got a valid ADVERTISE after 5ms
odhcp6c[11609]: IA_NA 0001 T1 1800 T2 2880
odhcp6c[11609]: 2a0f:ff00:abcd:0123::1 preferred 3600 valid 86400
odhcp6c[11609]: IA_PD 0001 T1 21600 T2 32400
odhcp6c[11609]: 2a0f:ff00:15b:1c00::/56 preferred 43200 valid 86400
odhcp6c[11609]: Starting REQUEST transaction (timeout 4294967295s, max rc 10)
odhcp6c[11609]: Send REQUEST message (elapsed 0ms, rc 0)
odhcp6c[11609]: Got a valid REPLY after 6ms
odhcp6c[11609]: Server returned IA_PD status 'No Address Available (No addresses have been assigned)'
odhcp6c[11609]: IA_PD 0001 T1 21600 T2 32400
odhcp6c[11609]: 2a0f:ff00:29a:7d00::/56 preferred 43200 valid 86400
odhcp6c[11609]: (re)starting transaction on pppoe-wan
odhcp6c[11609]: Starting SOLICIT transaction (timeout 4294967295s, max rc 0)
odhcp6c[11609]: Got a valid ADVERTISE after 6ms
odhcp6c[11609]: IA_NA 0001 T1 1800 T2 2880
odhcp6c[11609]: 2a0f:ff00:abcd:4567::1 preferred 3600 valid 86400
odhcp6c[11609]: IA_PD 0001 T1 21600 T2 32400
odhcp6c[11609]: 2a0f:ff00:15b:1c00::/56 preferred 43200 valid 86400
odhcp6c[11609]: Starting REQUEST transaction (timeout 4294967295s, max rc 10)
odhcp6c[11609]: Send REQUEST message (elapsed 0ms, rc 0)
odhcp6c[11609]: Got a valid REPLY after 6ms
odhcp6c[11609]: Server returned IA_PD status 'No Address Available (No addresses have been assigned)'
...
odhcp6c[11609]: 2a0f:ff00:abcd:0123::1 preferred 3600 valid 86400
suggests (I believe) that I have received a /56 prefix, but it seems that odhcp6c has an issue with the response or is expecting something different?
I tried creating a tcpdump while manually running odhcp6c, and here is the result:
root@OpenWrt:~# tcpdump -i pppoe-wan -n -vv '(udp port 546 or 547) or icmp6'
tcpdump: listening on pppoe-wan, link-type LINUX_SLL (Linux cooked v1), snapshot length 262144 bytes
12:23:20.005883 IP6 (flowlabel 0xa7d80, hlim 255, next-header ICMPv6 (58) payload length: 8) fe80::197a:902f:fd36:8687 > ff02::2: [icmp6 sum ok] ICMP6, router solicitation, length 8
12:23:20.110173 IP6 (class 0xc0, hlim 255, next-header ICMPv6 (58) payload length: 48) fe80::6aab:9ff:bc1b:c001 > fe80::197a:902f:fd36:8687: [icmp6 sum ok] ICMP6, router advertisement, length 48
hop limit 64, Flags [none], pref medium, router lifetime 4500s, reachable time 0ms, retrans timer 0ms
prefix info option (3), length 32 (4): 2a0f:ff00:abcd:1234::/64, Flags [onlink, auto], valid time 86400s, pref. time 3600s
0x0000: 40c0 0001 5180 0000 0e10 0000 0000 2a0f
0x0010: ff00 abcd 1234 0000 0000 0000 0000
12:23:20.776325 IP6 (flowlabel 0xb21fb, hlim 1, next-header UDP (17) payload length: 110) fe80::197a:902f:fd36:8687.546 > ff02::1:2.547: [udp sum ok] dhcp6 solicit (xid=c8effb (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 e45f01ec4252) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:1 T1:0 T2:0) (IA_PD IAID:1 T1:0 T2:0))
12:23:20.781648 IP6 (class 0xc0, hlim 255, next-header UDP (17) payload length: 165) fe80::6aab:9ff:bc1b:c001.547 > fe80::197a:902f:fd36:8687.546: [udp sum ok] dhcp6 advertise (xid=c8effb (server-ID hwaddr type 1 68ab099ac001) (client-ID hwaddr type 1 e45f01ec4252) (IA_NA IAID:1 T1:1800 T2:2880 (IA_ADDR 2a0f:ff00:abcd:81bc::1 pltime:3600 vltime:86400)) (IA_PD IAID:1 T1:21600 T2:32400 (IA_PD-prefix 2a0f:ff00:207:ed00::/56 pltime:43200 vltime:86400)) (DNS-server 2001:4860:4860::8888 2001:4860:4860::8844))
12:23:22.821479 IP6 (flowlabel 0xb21fb, hlim 1, next-header UDP (17) payload length: 179) fe80::197a:902f:fd36:8687.546 > ff02::1:2.547: [udp sum ok] dhcp6 request (xid=86486a (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 e45f01ec4252) (server-ID hwaddr type 1 68ab099ac001) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:1 T1:0 T2:0 (IA_ADDR 2a0f:ff00:abcd:81bc::1 pltime:3600 vltime:86400)) (IA_PD IAID:1 T1:0 T2:0 (IA_PD-prefix 2a0f:ff00:207:ed00::/56 pltime:43200 vltime:86400)))
12:23:22.827109 IP6 (class 0xc0, hlim 255, next-header UDP (17) payload length: 174) fe80::6aab:9ff:bc1b:c001.547 > fe80::197a:902f:fd36:8687.546: [udp sum ok] dhcp6 reply (xid=86486a (server-ID hwaddr type 1 68ab099ac001) (client-ID hwaddr type 1 e45f01ec4252) (IA_NA IAID:1 T1:0 T2:0 (status-code NoAddrsAvail)) (IA_PD IAID:1 T1:21600 T2:32400 (IA_PD-prefix 2a0f:ff00:207:ed00::/56 pltime:43200 vltime:86400)) (DNS-server 2001:4860:4860::8888 2001:4860:4860::8844))
12:23:23.280857 IP6 (flowlabel 0xb21fb, hlim 1, next-header UDP (17) payload length: 110) fe80::197a:902f:fd36:8687.546 > ff02::1:2.547: [udp sum ok] dhcp6 solicit (xid=29c7af (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 e45f01ec4252) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:1 T1:0 T2:0) (IA_PD IAID:1 T1:0 T2:0))
12:23:23.286274 IP6 (class 0xc0, hlim 255, next-header UDP (17) payload length: 165) fe80::6aab:9ff:bc1b:c001.547 > fe80::197a:902f:fd36:8687.546: [udp sum ok] dhcp6 advertise (xid=29c7af (server-ID hwaddr type 1 68ab099ac001) (client-ID hwaddr type 1 e45f01ec4252) (IA_NA IAID:1 T1:1800 T2:2880 (IA_ADDR 2a0f:ff00:abcd:81cc::1 pltime:3600 vltime:86400)) (IA_PD IAID:1 T1:21600 T2:32400 (IA_PD-prefix 2a0f:ff00:207:ed00::/56 pltime:43200 vltime:86400)) (DNS-server 2001:4860:4860::8888 2001:4860:4860::8844))
12:23:24.641398 IP6 (flowlabel 0xb21fb, hlim 1, next-header UDP (17) payload length: 179) fe80::197a:902f:fd36:8687.546 > ff02::1:2.547: [udp sum ok] dhcp6 request (xid=b561aa (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 e45f01ec4252) (server-ID hwaddr type 1 68ab099ac001) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:1 T1:0 T2:0 (IA_ADDR 2a0f:ff00:abcd:81cc::1 pltime:3600 vltime:86400)) (IA_PD IAID:1 T1:0 T2:0 (IA_PD-prefix 2a0f:ff00:207:ed00::/56 pltime:43200 vltime:86400)))
12:23:24.646860 IP6 (class 0xc0, hlim 255, next-header UDP (17) payload length: 174) fe80::6aab:9ff:bc1b:c001.547 > fe80::197a:902f:fd36:8687.546: [udp sum ok] dhcp6 reply (xid=b561aa (server-ID hwaddr type 1 68ab099ac001) (client-ID hwaddr type 1 e45f01ec4252) (IA_NA IAID:1 T1:0 T2:0 (status-code NoAddrsAvail)) (IA_PD IAID:1 T1:21600 T2:32400 (IA_PD-prefix 2a0f:ff00:207:ed00::/56 pltime:43200 vltime:86400)) (DNS-server 2001:4860:4860::8888 2001:4860:4860::8844))
12:23:24.648447 IP6 (flowlabel 0xb21fb, hlim 1, next-header UDP (17) payload length: 110) fe80::197a:902f:fd36:8687.546 > ff02::1:2.547: [udp sum ok] dhcp6 solicit (xid=5c70bd (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 e45f01ec4252) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:1 T1:0 T2:0) (IA_PD IAID:1 T1:0 T2:0))
12:23:24.653883 IP6 (class 0xc0, hlim 255, next-header UDP (17) payload length: 165) fe80::6aab:9ff:bc1b:c001.547 > fe80::197a:902f:fd36:8687.546: [udp sum ok] dhcp6 advertise (xid=5c70bd (server-ID hwaddr type 1 68ab099ac001) (client-ID hwaddr type 1 e45f01ec4252) (IA_NA IAID:1 T1:1800 T2:2880 (IA_ADDR 2a0f:ff00:abcd:81d4::1 pltime:3600 vltime:86400)) (IA_PD IAID:1 T1:21600 T2:32400 (IA_PD-prefix 2a0f:ff00:207:ed00::/56 pltime:43200 vltime:86400)) (DNS-server 2001:4860:4860::8888 2001:4860:4860::8844))
12:23:26.523391 IP6 (flowlabel 0xb21fb, hlim 1, next-header UDP (17) payload length: 179) fe80::197a:902f:fd36:8687.546 > ff02::1:2.547: [udp sum ok] dhcp6 request (xid=f79596 (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 e45f01ec4252) (server-ID hwaddr type 1 68ab099ac001) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:1 T1:0 T2:0 (IA_ADDR 2a0f:ff00:abcd:81d4::1 pltime:3600 vltime:86400)) (IA_PD IAID:1 T1:0 T2:0 (IA_PD-prefix 2a0f:ff00:207:ed00::/56 pltime:43200 vltime:86400)))
12:23:26.528997 IP6 (class 0xc0, hlim 255, next-header UDP (17) payload length: 174) fe80::6aab:9ff:bc1b:c001.547 > fe80::197a:902f:fd36:8687.546: [udp sum ok] dhcp6 reply (xid=f79596 (server-ID hwaddr type 1 68ab099ac001) (client-ID hwaddr type 1 e45f01ec4252) (IA_NA IAID:1 T1:0 T2:0 (status-code NoAddrsAvail)) (IA_PD IAID:1 T1:21600 T2:32400 (IA_PD-prefix 2a0f:ff00:207:ed00::/56 pltime:43200 vltime:86400)) (DNS-server 2001:4860:4860::8888 2001:4860:4860::8844))
12:23:27.090702 IP6 (flowlabel 0xb21fb, hlim 1, next-header UDP (17) payload length: 110) fe80::197a:902f:fd36:8687.546 > ff02::1:2.547: [udp sum ok] dhcp6 solicit (xid=71b89a (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 e45f01ec4252) (reconfigure-accept) (Client-FQDN) (IA_NA IAID:1 T1:0 T2:0) (IA_PD IAID:1 T1:0 T2:0))
12:23:27.096071 IP6 (class 0xc0, hlim 255, next-header UDP (17) payload length: 165) fe80::6aab:9ff:bc1b:c001.547 > fe80::197a:902f:fd36:8687.546: [udp sum ok] dhcp6 advertise (xid=71b89a (server-ID hwaddr type 1 68ab099ac001) (client-ID hwaddr type 1 e45f01ec4252) (IA_NA IAID:1 T1:1800 T2:2880 (IA_ADDR 2a0f:ff00:abcd:81e1::1 pltime:3600 vltime:86400)) (IA_PD IAID:1 T1:21600 T2:32400 (IA_PD-prefix 2a0f:ff00:207:ed00::/56 pltime:43200 vltime:86400)) (DNS-server 2001:4860:4860::8888 2001:4860:4860::8844))
^C
16 packets captured
17 packets received by filter
0 packets dropped by kernel
Maybe someone here knows how to get odhcp6c to properly handle the delegation.