#openports

Port Number in Cybersecurity | Open Ports | Closed Ports | Filtered Ports

Ports - a way to help system to identify, establish and transmit data from one side to another. Once a port is running on one number, you cannot use the same port number for the other service to run.  

All these ports by which you are communicating -- Open Ports. So you see, open ports are dangerous, if it could be find out by someone. it could lead to tell an attacker what services are running on your system. 

Once it is found by the attacker that target system using this service, he will try to find out relevant vulnerabilities of that service and later using that vulnerability he gonna try to attack you. 

Tools - Nmap for Linux , Zenmap for Windows 

NOTE : Make sure you never use these tools without prior permission from the target. 

Closed Ports - Services on which it is not listening it is closed. 

Filtered Ports - When a request packet is sent but no reply is received, indicates the packet has been filtered and dropped by the firewall which is protecting the port.