TCP and UDP services use Listeners to accept incoming connections and packets. Each Listener can use one or several listener sockets.
A listener socket accepts incoming TCP connections or receives UDP packets on the port number you specify. You should also specify if the socket should accept connections or receive packets on all IP addresses your server computer has, or only on a selected address.
For example, you may want to create a socket that accepts all connections on one local IP address, while the other socket is used to accept connections on the other local IP address - and only from the specified networks.
Because of the nature of TCP sockets, you cannot have two listener sockets that use the same port number and the same local IP address: if you create a listener socket on the TCP port N that works with ALL local IP addresses, you cannot create a different socket on the same port N. If you create a listener socket on the TCP port N and a specific local address xx.xx.xx.xx, then you can create a different listener socket on the same TCP port N and a different local address yy.yy.yy.yy.
If your CommuniGate Pro Server coexists with some other server software, such as a third-party Web server, you may want to configure that Web server to use one local IP address, while your CommuniGate Pro server would provide its HTTP services on a different local IP address - but on the same port number. If that port number is 80, and the domain name www.company.com resolves into the first IP address, while mail.company.com resolves into the second IP address, then typing http://www.company.com in a client browser will bring up the third-party Web Server home page, while typing http://mail.company.com will bring up the CommuniGate Pro Login page - with both servers running on the same server computer.
To create a new listener socket, change the value in the last table element from 0 to the desired port number and click the Update button.
To remove a listener socket, change its port number to 0 and click the Update button.
Even if your server has only one IP address, you may want to create two listener sockets for most of your TCP services: one for regular, clear text connections and one (on a different port number) for secure connections (see below).