Port inaccessible from outside, but accessible locally

Hello,
I'm running a Debian 7 server in a VM.
Most of the functionality works, I can connect to the DB via port 80, but
when I try to access port 9200 I get this error:
publish_address {127.0.0.1:9200}, bound_addresses {[::1]:9200}, {127.0.0.1:9200}

Oddly enough the port is internally accessible from within (localhost) and everything works fine.
I think this error has something to do with IPv6, because of the '::' in the error, but not sure what to do about this.

Any ideas?

I'm not sure what kind of DB you are talking about, but it might be clear error in configuration.
If you have on the DB server binding configured only for ::1 or 127.0.0.1 then it is just a internal network interface. And it is consistent with what you are telling about trying to connect.

If that is the case, then you would need to change configuration to open port on either 0:0:0:0 (all network interfaces or IP6 equivalent) or to very specific network interface (in case of some security considerations).

But to be honest in such case, I expect might be happening, the client should either tell something like "connection refused" or in some cases "timeout".

So maybe explain what service you are trying to connect and from what client.