This feature is currently not available (although has been asked for quite a bit, so hopefully in a future release). Currently the only way to assign users a specific address is to create a specific group with an IP address pool with one address in it. I know this is not scalable, but it's the only way at the moment.
If you really want this feature, please have your Account Mgr or SE add in a feature enhancement for it, the more people that ask for it the more likely it'll get added quicker.
We have configured the outside and inside Interface with official ipv6 adresses, set a default route on outside Interface to our router, we also have definied a rule , which also gets hits, to permit tcp from inside Interface to any6.
In Syslog I also se...