Optionally, you may restrict the port range for data connections.

When an FTP client logs in to a server, a connect request always flows from the client to the server to establish a control connection. When a client wants to transfer data, for example with a get command, a different connection, referred to as a data connection, must be established to handle the transfer. Unlike the control connection, there are multiple ways a data connection can be established. The server can initiate the connect request or the client can initiate the connect request, depending on the level of FTP RFC support.

You may restrict which ports are used for data connections for the cases where the clients use firewall friendly protocols. While the client opens the data connection, it is the server that tells the client which port to connect to. By specifying the lower and upper range, you direct the server to pick a data connection port within the specified range. The server randomly selects a port within the range. This may be helpful in defining firewall policies to accommodate the range of ports FTP data connections will use.

The specified range of ports are reserved for FTP by coding the PORTRANGE configuration statement, with the AUTHPORT parameter, in PROFILE.TCPIP. Msys automatically does this reservation for you. If any of the ports in the range are already reserved for another application, you will be asked if you want to negate the other application's reservation. A complete list of port reservations can be seen in the Basic Settings task.

The port range specification for data connections not using firewall friendly protocols has no effect.

Syntax rules: