Subject Firebird can't connect to host
Author Andromeda

I'm new in FirebirdSQL. I can't connect into my host address whereas it can connect to localhost successfully. It prompt show errors like this:

SQL> connect "" user 'SYSDBA' password 'masterkey';
Statement failed, SQLSTATE = 08006
Unable to complete network request to host "".
-Failed to establish a connection.

I have Googled about this for almost a month but I can't find the absolute way to solve this problem. My ufw firewall already deactivated, the port 3050 is opened, but it still can't connect into my host address, but easily connect to the The Firebird classic server is running on Lubuntu Desktop 14.04.1 and the version of Firebird is 2.5.

This problem occured since I reinstall/upgrading my OS from into Lubuntu version. On the previous OS, I never facing an error like this.

What's going wrong here?
Whether this problem related to OS version, or just a dumb error that I can't solve, I don't know and I very need an help from the experts, please.

Any help would be very appreciated, thank a lot in advance.