I am on Mint Linux 19.1 and trying to access our database via a VPN connection (no ssh tunnel). I can connect fine if I enter the database IP address, but if I put in the internal database domain name (we are on AWS), it fails to resolve the name. I can resolve the name fine on the command line using nslookup or dig.
I have resolved the issue. It was not a problem with DBVisualizer, but was related to systemd-resolved and how it handles VPN DNS.
For those in the same situation, here is how I resolved it.
1. Modify the conf file link for systemd-resolved
sudo rm /etc/resolv.conf
sudo ln -sf /run/systemd/resolve/resolv.conf /etc/resolv.conf
2. Update the order of resolution in /etc/nsswitch.conf, by placing the dns before the mdns4_minimal
sudo vi /etc/nsswitch.conf
move dns from the end of the line before mdns4_minimal