IPv6in4 tunnel with only one /64 prefix

[Frédéric Perrin]

Hello list,

I have a FreeBSD server with native IPv6 connectivity. At home, my ISP
provides me with only IPv4 connectivity. In order to get IPv6 to the
home, I had the idea of creating a 6in4 tunnel between my home gateway
and my FreeBSD server. The part about creating the tunnel, routing
between the home and the server works using private addresses (fc00::/8
over gif0).

However, I only have one global /64 on the FreeBSD box. What can I do?

I have the idea of subnetting the /64 into e.g. /80, route a couple of
/80s through gif to the home and use another /80 for the FreeBSD server.
However, as the router into which my FreeBSD server is connected will
expect the entire /64 to be directly connected, I will have to setup
some kind of NDP proxy for the /80 to the home. I will also lose
autoconf, but I can live with that.

Comments, either on the plan above, or something else I haven't thought
of?

-- 
Fred