I have a ftp server in my inside zone of ASA, One of my application team needed to access that ftp server in the inside interface with the Public IP. If they were using a url for that I could have used "dns doctoring". I tried with the following NAT
static (inside, inside) <localip> <publicip>
but ASA thinking that it is an attack
Note: Both Client and FTP server are in the same network hence the zone which is inside.
Correct, if you already have NAT statement on that interface, then you would need the global (inside) command. Otherwise, if there is no NAT statement at all on that interface, you can disable nat-control, and the connection would work.
Also, if you have ACL assigned to the inside interface, you would need to allow the traffic:
access-list permit tcp host eq 21