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