[6bone] link local for tunnel endpoints

[Dan Reeder]

Hey guys
in light of the recent spirited discussions regarding ptp subnets, I was
wondering whether anyone has used or is using the link local addressing for
the endpoints. (I'm not too sure whether it is still called link local in
this case, as it is quite different from typical MAC-based addressing)

here's an example of my tunnel:

ip tunnel add sixbone mode sit remote 203.149.69.35 local 202.173.147.67
ip link set sixbone up
ip tunnel change sixbone ttl 255
ip link set mtu 1472 dev sixbone
route add -A inet6 ::/0 gw fe80::cb95:4523 dev sixbone

fe80::cb95:4523 is just the remote ip converted to hex and set with a link
local prefix.

Now because my local router and the remote router also have valid 2001::
global addressing (on mine for the /64 on another interface, on the remote
for other purposes), so traceroutes back and forth are going through just
fine. I realise that every device needs a globally reachable ip set on it
somewhere, even on a loopback interface, to be reachable.
But are there any operational down sides or gotchas that would prove this
type of addressing to be unsafe or impractical for use?

thanks
Dan Reeder