2) There could be a number of things that can contribute to the firewall being in hung state. A few example would be if the ASA is being attacked, if the ASA is overloaded, if the ASA hits a bug due to specific condition, if memory leaks on the ASA, etc etc.
When the ASA is in hung state, it's important to at least grab a copy of the "show tech" output via console (if console did not hang), then depending on what the actual issue that triggers the hung state, TAC engineer will ask for more output.
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...