DNS is needed only if the A record or address record need to be rewritten in the DNS replies that match the static command.
For DNS replies traversing from a mapped interface to a real interface, the A record is rewritten from the mapped value to the real value. Inversely, for DNS replies traversing from a real interface to a mapped interface, the A record is rewritten from the real value to the mapped value.
To make your troubleshooting clean (no issues with name, etc), using address instead of name. Also, test the acl with one server at a time. See if the access from inside to dmz works. Test if both side is reachable va ping/icmp. Check the acl hitcount as well (use sh 'access-list acl-in' command).
access-list acl_in permit icmp any any --> allow ping for testing purposes only, remove later.
access-list acl_in permit tcp any host 172.16.31.10 eq sqlnet log
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...