Typically the firewall is operating in your network router connected to the Internet. This does not require any additional set up.
If the firewall is between your Mac running KymaConnect and your iDevice then you will have to set it up to allow network traffic between the Mac and your iDevice. We discourage this usage as it greatly complicates set up. For more information about a firewall between your Mac and iDevice, see the corresponding question in the vKiP FAQ’s
If the firewall is between your Mac and the Paca(rana) this also requires firewall set up. Again we discourage this type of configuration and recommend that your Mac, Paca(rana), and iDevice all connect behind the same firewall.
If your Mac is running OSX's built-in firewall then you still have to set it up to allow KymaConnect to communicate with your iDevice, and for KymaConnect to communicate with your Paca(rana). The built-in firewall should prompt you the first time you run PacaConnect to ask for permission to use the appropriate ports. However, KymaConnect normally uses dynamically assigned ports, meaning that the ports used can change each time you run it. KymaConnect attempts to reuse the same ports it used previously but if some other application is using them KymaConnect will use different ports, and the firewall will again ask you for permission to use those ports. The port numbers are in the range 49,152 - 65,535, and the network traffic type is "UDP".
If you use another type of firewall and are unable or unwilling to open up the required ports then you will no longer be able to benefit from dynamic port assignment. You can use the "Force port 8000" option on the preference panel to partially address this but the port used to connect to the Paca(rana) does not have such a preference setting. However there is a work around. Please contact support (email@example.com) and we will be happy to provide instructions.