Can odhcpd assign /112 ipv6?

is there a way to auto assign /112 ipv6 to clients? I get /64 from isp, but I hope to subnet it to /112, the manuaully setup is ok. can odhcpd assign /112 ipv6?

short answer: no.

subnets with more bits than /64 break Android phones and various other devices that expect to do auto config.

handing out a /64 is broken, your ISP is stupid, I'm sorry for that, but it's true.


If your ISP gives you only/64, you can use IPv6 relay mode.
(The relay mode is meant to provide IPv6 on LAN even if there is no prefix delegation)

See wiki.


that is to say all device windows/linux must using manually setting up in order to use /112? dhcp v6 and slaac all does not support prefix greater than /64?

relay? i see some articles says that to use
nddpd to broadcast prefix(x:x:x:x::/64 in lan)
ip -6 neigh add x:x:x:x:10::1/64 dev eth0
and ip -6 route add x:x:x:x:10::1/64 dev eth1
ip -6 neigh add x:x:x:x:10::2/64 dev eth0
and ip -6 route add x:x:x:x:10::2/64 dev eth1
ip -6 neigh add x:x:x:x:20::1/64 dev eth0
and ip -6 route add x:x:x:x:20::2/64 dev eth2
ip -6 neigh add x:x:x:x:20::2/64 dev eth0
and ip -6 route add x:x:x:x:20::2/64 dev eth2
(using linux as gateway, eth0 x:x:x:x:a:b:c:d/64 is connected with internet eth1 x:x:x:x:10::x is local lan port eth2 x:x:x:x:20::x is a scond local lan port)
is it similar with this situation?

Specific relay mode, set in normal openwrt uci config.
See here (the relay example where wan IPv6 gets relayed to LAN. Settings in both sections)