OOB Logoff feature is coming in 4.8, out due this summer. Currently NAC has no way of knowing when a machine is logged off behind an IP phone. If the machine is shutdown however and brought back up again, it should generate a mac-notification which would place the port in the auth vlan again.
Make sure you're using Mac-Notification for your switches also.
I currently do shut down my laptop and bring it home over night. The next morning when I connect it to my IP phone, it still is not prompted with a log in. I currently do have MAC-Notification turned on.
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...