IPv4/IPv6 router

[Frederic Beck <frederic.beck@loria.fr>]

Hello

I'm aiming at setting up an IPv4/IPv6 router based on a Debian
distribution.

My network has a native IPv6 connection, but i would like to have my own
sub-network with my own prefixe.

M idea was to use a PC an set up a router which would be transparent for
IPv4 (the whole network is protected by a FW, i only need to act as a
gateway, i don't nedd to set a NAT, the hosts have IPv4 assigned
adresses via a DHCP which is outside of the LAN), and who would not do
any filtering for IPv6, only advertise my prefixe with radvd.

For the Netfilter conf, i think i just need to enabled the forwarding
for both IPv4 and IPv6, and configure radvd to advertise the prefixe on
my LAN interface.

For this, i have a few questions : 

- is it correctly supported under debian ?
- what do i need to do to ensure the routing for my LAN in IPv6 with the
rest of the network ?
- can i avoid setting a NAT for IPv4 ?

thanks
Fred