On Sat, 22 Aug 2009 12:47:52 +0200, Sascha Hlusiak
[off-list ref] wrote:

Using only the actual destination address to determine the IPv4 target in
try_6to4(&iph6->daddr) seems wrong to me and breaks, if a 6to4 address is
the next-hop, like ::192.88.99.1 written as 6to4:

default via 2002:c058:6301:: dev 6to4

A package to 2001:: would fall through the try_6to4 check to the
IPv4-compat check and die there.

I don't understand what you're trying to fix. For a 6to4 tunnel, this has
always worked fine for me, as far as I remember:
default via ::192.88.99.1 dev 6to4

This patch makes try_6to4 use the address of the Next-Hop instead,
respecting
the routing table. Users are encouraged to have a route 2002::/16 to the
tunnel device anyway, making all other 6to4 hosts direct neighbours.

And where exactly is that "encouragement" coming from?

-- 
Rémi Denis-Courmont