Can there be any traffic leaks beside the vpn connection?Generally there can be traffic leaks beside OpenVPN. This is because of both OpenVPN settings adjustment and operation system settings on clients computer.
When you work with our service DoubleVPN.com using common OpenVPN client there can be traffic leak only after disconnect command comes from client or from server.
Such command can come from client side as you disconnect from subscription manually or get disconnected by operation system as your computer switches to sleep mode. We see two possible solutions here: either you can disable sleep mode on your computer or forbid other software (for example, messengers) to automatically reconnect after disconnect (also when operation system starts after sleep mode).
From server side our clients are protected even in case of subscription expiration at the moment you are connected to it. We don't disconnect you from vpn when your subscription expires so your traffic cannot leak. Other vpn services may have traffic leaks at subscription expiration when you are using it.
Thus you don't need any additional software (firewall etc.) when you work with our service DoubleVPN.com. OpenVPN client will not let traffic pass by until you manually disconnect from subscription (for example, [double]-DE-UK-over-TCP). The worst thing that can happen is the OpenVPN icon in tray turns yellow, this means connection problems (at such moments no software can connect to Internet).