Port property specifies what local port is used for
accepting new connections. Its default value 21 is used for
FTP protocols, and default value 22 when SFTP protocol is
selected. You may change it to something else. If you do
so, please notify users that will use your server for new
port number.
When you change this value, please be sure that selected
port is 'not taken' by some other application. If
you're not sure if it's available or not, easiest
way to find out is to execute 'netstat -a' from
command prompt and check if there's '21' or
'22' value listed in 'Local Address'
column. In default installations of all Windows operating
systems, no FTP server will be installed so you don't
have to worry about this.
You cannot change value of this property when your
server is running. If you want to change it, first Stop the server, change
the port, and then Start it again. If
there are any users connected at that time, they will be
disconnected.