I have got one firewall, with a public IP (dynamic) provided by my ISP.
As the IP is dynamic, I registered a domain in the service NO-IP as not to worry whether the IP changes anymore.
The problem:
Looks like my ISP is also giving a name for that IP, so when I resolve it (standard DNS configured, such 8.8.8.8) it would resolve the name in favour of my ISP.
The key point:
¿Is there any way to "OVERRIDE" the name given by the ISP with the one registered in NO-IP, in order to ALWAYS resolve to the no-ip name?
Thanks!
Whatever you did with NO-IP/DDNS, it will have no effect on Reverse DNS lookup. Reverse DNS is controlled by whoever "owns" the IP address, usually your ISP, so they would have to change the record according to your request (or sub-delegate it to your DNS servers) which they will almost certainly not do since you have dynamic IP address.