Gave up trying to get a sensible answer from my provider so, I have changed my config so my OpenWrt router is now sitting behind my ISP router.
For DHCPv6 I have set the wan6 interface to master and enabled "relay" for dhcp, ra & ndp for both the lan and wan6 interfaces.
Everything appears to be working with one exception, I can't access the OpenWrt router from the LAN devices using IPv6.
The LAN configuration doesn't look correct to me.
OpenWrt router:
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq master br-lan state UP qlen 1000
link/ether 10:7b:44:59:9b:1c brd ff:ff:ff:ff:ff:ff
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
link/ether 10:7b:44:59:9b:18 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.100/24 brd 192.168.1.255 scope global eth1
valid_lft forever preferred_lft forever
inet6 fd00::127b:44ff:fe59:9b18/64 scope global noprefixroute
valid_lft forever preferred_lft forever
inet6 2a01:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx/128 scope global dynamic noprefixroute
valid_lft 57625sec preferred_lft 43225sec
inet6 fe80::127b:44ff:fe59:9b18/64 scope link
valid_lft forever preferred_lft forever
6: br-lan: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP qlen 1000
link/ether 10:7b:44:59:9b:1c brd ff:ff:ff:ff:ff:ff
inet 192.168.10.1/24 brd 192.168.10.255 scope global br-lan
valid_lft forever preferred_lft forever
inet6 fd81:250d:683a::1/60 scope global noprefixroute
valid_lft forever preferred_lft forever
inet6 fe80::127b:44ff:fe59:9b1c/64 scope link
valid_lft forever preferred_lft forever
7: vpn: <POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1420 qdisc noqueue state UNKNOWN qlen 1000
link/[65534]
inet 192.168.12.1/24 brd 192.168.12.255 scope global vpn
valid_lft forever preferred_lft forever
inet6 fdf1:e8a1:8d3f:12::1/64 scope global
valid_lft forever preferred_lft forever
8: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-lan state UP qlen 1000
link/ether 10:7b:44:59:9b:18 brd ff:ff:ff:ff:ff:ff
inet6 fe80::127b:44ff:fe59:9b18/64 scope link
valid_lft forever preferred_lft forever
9: tun0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UNKNOWN qlen 500
link/[65534]
inet 192.168.11.1/24 scope global tun0
valid_lft forever preferred_lft forever
inet6 fe80::6564:76d0:e35a:6f2c/64 scope link flags 800
valid_lft forever preferred_lft forever
10: wlan1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-lan state UP qlen 1000
link/ether 10:7b:44:59:9b:1c brd ff:ff:ff:ff:ff:ff
inet6 fe80::127b:44ff:fe59:9b1c/64 scope link
valid_lft forever preferred_lft forever
11: wlan0-1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-lan state UP qlen 1000
link/ether 12:7b:44:59:9b:18 brd ff:ff:ff:ff:ff:ff
inet6 fe80::107b:44ff:fe59:9b18/64 scope link
valid_lft forever preferred_lft forever
12: wlan1-1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-lan state UP qlen 1000
link/ether 12:7b:44:59:9b:1c brd ff:ff:ff:ff:ff:ff
inet6 fe80::107b:44ff:fe59:9b1c/64 scope link
valid_lft forever preferred_lft forever
LAN device:
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: enp6s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc fq_codel state DOWN group default qlen 1000
link/ether 00:e0:4c:77:16:f5 brd ff:ff:ff:ff:ff:ff
3: enp0s31f6: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc fq_codel state DOWN group default qlen 1000
link/ether 40:8d:5c:52:31:eb brd ff:ff:ff:ff:ff:ff
7: wlp0s20f0u9: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether bc:a5:11:36:fc:f3 brd ff:ff:ff:ff:ff:ff
inet 192.168.10.2/24 brd 192.168.10.255 scope global dynamic noprefixroute wlp0s20f0u9
valid_lft 42771sec preferred_lft 42771sec
inet6 2a01:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx/64 scope global dynamic noprefixroute
valid_lft 57596sec preferred_lft 43196sec
inet6 fd00::a7fe:e926:12a8:651c/64 scope global noprefixroute
valid_lft forever preferred_lft forever
inet6 fe80::cdc3:3798:94cf:d812/64 scope link noprefixroute
valid_lft forever preferred_lft forever
ula_prefix is:
fd81:250d:683a::/48
Shouldn't the Unique Local Address for the LAN devices be in this subnet so they are the same as the OpenWrt router? If yes, how I do I change this?
Thanks.