To check open ports on your Linux system you will need following package: nmap

Debian/Ubuntu got his package in standard repository already for ages.
Installing the nmap.

To have simple check play with your local host IP, usually it’s 127.0.0.1.  To do so, type: nmap -sS -O 127.0.0.1

In this example it’s clear which port are open:

22/tcp    open  ssh
139/tcp   open  netbios-ssn
445/tcp   open  microsoft-ds
3306/tcp  open  mysql
10000/tcp open  snet-sensor-mgmt