ip6hint
: Subprefix ID to be used if available (e.g. 1234 with an ip6assign of 64 will assign prefixes of the form …:/64 or given LAN ports, LAN & LAN2, and a prefix delegation of /56, use ip6hint of 00 and 80 which would give prefixes of LAN …:xx00::/64 and LAN2 …:xx80::/64)
ip6assign
and / orip6hint
settings might be ignored if the desired subprefix cannot be assigned. In this case, the system will first try to assign a prefix with the same length but different subprefix-ID. If this fails as well, the prefix length is reduced until the assignment can be satisfied. Ifip6hint
is not set, an arbitrary ID will be chosen. Setting theip6assign
parameter to a value < 64 will allow the DHCPv6-server to hand out all but the first /64 via DHCPv6-Prefix Delegation to downstream routers on the interface. Ifip6hint
is not suitable for the givenip6assign
, it will be rounded down to the nearest possible value.
https://openwrt.org/docs/guide-user/network/ipv6/configuration