How to configure a tunnel

[Masaki Hirabaru]

6bone folks,

I previously reported how to make a configured tunnel on inria
ipv6 freebsd version, but I found another better way.

If you use a configuration similar to that I posted before, you
will see that all outgoing packets generated on that machine for
the configured tunnel have a compatible address as its source,
which means that returning packets will be through automatic
tunneling. I learned how the inria ipv6 implemented configured
tunneling, and found the following way.

ifconfig sit0 inet6 fe80::c0:f000:e59a
route -n add -inet6 -net fe80::c051:6042/128 ::192.168.10.103
ifconfig sit0 inet6 5f00:ed00:c66c:3c00::153
route -n add -inet6 -net 5f00:ed00:c0a8:0a00::/80 ::192.168.10.103

In this case, the destination has a link-local address as well as
a global one. When sending a packet destined to one of them, its
source address will be corresponding one. I believe this doesn't
affect automatic tunneling.

Masaki