title: Google Compute VM's as DNS servers not working
body: <p>I have little experience with DNS servers, the experience i do have is limited to creating zones and managing subdomains and stuff like that - pretty basic. I've been experiencing some problems to setup a master and slave dns server do host my domains within Google Cloud. I have setup the both servers and tested it from inside google cloud network, when i try to use it externally - like registering a new domain and point its zone there it doesn't work.. I can't reach the server. When i try a "dig -x IPADDR" from outside i get a Google Cloud like reverse DNS, i can't reach my server. I have already added the port 53 tcp and udp on the firewall, but still nothing. Could someone give me some adivice on how to proceed so i can make it work?</p>