Firewall

Although firewalls are necessary, there can be network port conflicts that occur when a firewall is in place. This is particularly true when running CygNet.

The Windows Firewall will prevent CygNet clients from communicating with a CygNet server. Rather than disabling the firewall, you can allow "exceptions" for the CygNet service ports that are in use by your system. These changes only need to be made on the host server. Client computers are not affected.

When adding the port exceptions, the port type is UDP (User Datagram Protocol). Similar to TCP/IP running on top of Internet Protocol (IP) networks, UDP is a connectionless protocol. Compared to TCP/IP, UDP presents a much lower network overhead due to how UDP processes network packets.

The Inbound UPD port must be opened for services to allow communication, although ports can be opened for both Inbound and Outbound communication. At a minimum, you must open the firewall for the UIS port.