You need to know the ports the system is listening on
You can use the "netstat -utl" command which will show you alle the tcp and udp ports the system is listening on.
With "netstat -tulp" you can also see the programs responsible for the ports. This output is very nice.
About the Author
Wim Peeters is electronics engineer with an additional master in IT and over 30 years of experience including time spent in support, development, consulting, training and database administration. Wim has worked with SQL Server since version 6.5. He has developed in C/C++, Java and C# on Windows and Linux in different European countries and different European languages. He writes knowledge base articles to solve IT problems and publishes them on the Lubby Knowledge Platform where he is one of the most important contributors and the main developer.