How is this different than the "IPv6 tunneling" option on mono's Advanced Setup page?
There is a very big difference.
The "IPv6 Tunneling" option that is already there only allows a tunnel of protocol 41 (IPv6 encapsulated in IPv4) to go
through the firewall and terminate on a device on the inside firewall.
Native support would mean to have IPv6 addresses on the wan and lan interfaces themselves and be able to build firewall rules with IPv6 addresses in them.
The DNS part would obviously also have to support v6
DHCP is not needed in the same way, as this function (handout of addresses to endhosts) is supported by default if you have a full IPv6 stack
A really useful feature would be to be able to hook m0n0wall up to a tunnel broker on the wan side in case your ISP does not support native v6.
Other Tunneling solutions for VPN and IPsec would be nice too
Topic: IPv6