How to monitor (check) services running on particular port

Nagios Nagios Configuration support
1

Dear all,

   I am new to nagios.

   we are using linux in large scale. 

   we have lot of customized softwares running on different ports.

   we want to monitor these ports.

  Ex: how to monitor 3306, 445, 7071, 8080 like this.

   pls help me
2

You can use check_tcp or check_udp plugin in order to get the port availability