I am having problems getting IPv6 to work under OpenWRT, I want to run it DHCPv6 stateful (like DHCPv4), but for some reason setting it to that (or stateless) in the LAN interface page will stop clients having internet access, bar having a valid (as far as I can see) IPv6 address and their DNS requests being seen and responded to by the router. The only way I have got it to work is with the stateless+stateful setting, but that seems to just decide to stop working after an hour or so (and I have to disconnect the client to get it working again).
config interface 'lan' option type 'bridge' option proto 'static' option netmask '255.255.255.0' option ipaddr '192.168.77.7' option ifname 'eth0.1' option ip6assign '56'
config dhcp 'lan' option interface 'lan' option start '100' option limit '150' option leasetime '12h' option ra 'server' option instance 'dnsmasq' option ra_default '1' option dhcpv6 'server' option ra_management '1'
What would be going wrong?