Find open ports
What are ports?
Ports allow computers/devices run multiple servers/applications.
A port number uses 16 bits, so it can have a value of 0 to 65535 decimal. If you have an open port, it is not dangerous.
An open port means a port through which anyone can try to connect to your network. You may wish to close these ports if you do not use them. Different ports and their numbers are used for different purposes. For example, ports 3000 and 3030 are used by software developers while port 80 is used by web access. Think of ports as open windows in a locked house. These two open ports act as windows while the router is the main door.
Open ports can impact the confidentiality, integrity, and availability of your organization/setup:
- Confidentiality: Open ports, and the programs listening and responding to them, can reveal information about the system or network architecture. Open ports can leak banners, software versions, content, the existence of the system itself, and what type of system it is.
- Integrity: Without open port controls, software can open any candidate port and immediately communicate unhindered. This is often relied upon for legitimate programs, as well as different types of malware.
- Availability: Your network and the services running on open ports still process incoming traffic, even if the requests are invalid. This can result in denial of service (DoS) attacks.
Port Scanner tool
The Port Scanner tool helps you find open ports.
When an application uses a service, it uses some ports. Once the application has used the ports, the ports become free. Once a port is free/not in use, the Fing App will tell you the port is open and no application is using it, thus advising you to close the port.
How to use the Fing open ports tool
- Click the Tools tab in the left sidebar
- Click Fing Open Ports. This will take you to the Port Scan page, where you can either enter a website or select the device on your network from the dropdown list. You can also change the ports scanned by the app. If you want to scan for all 65k ports or just the common ports.
Fing Mobile App
- Open Fing Mobile
- Click the Tools tab in the bottom toolbar
- Click Find open ports under the heading Improve your network security. This will open the Find open ports page, where you can either enter a website or select the device on your network from the dropdown list.
- Click the blue Find open ports button
The most common ports are:
- FTP (21)
- SSH (22)
- Telnet (23)
- SMTP (25)
- WHOIS (43)
- DNS (53)
- DHCP (67, 68)
- TFTP (69)
- HTTP (80)
- POP3 (110)
- SFTP (115)
- IMAP (143)
- SNMP (161)
- HTTPS (443)
- LPD (515)
- rsync (873)
- IMAP SSL (993)
- POP3 SSL (955)
- SOCKS (1080)
- Proxy (3128)
- MySQL (3306)
- RDP (3389)
- PostgreSQL (5432)
- VNC (5900)
- TeamViewer (5938)
- HTTP (8080)
When a router is involved, there is a risk of unwanted access finding its way through existing devices. Any application on a device may request that the router opens a port on its behalf for contact with an entity outside of your local network.
Test router vulnerabilities tool
On Fing Premium and Fing Starter, the Test router vulnerabilities tool on Fing Desktop prevents risks to your network and unauthorised open open ports. To do this:
- Click the Tools tab in the sidebar
- Click Test router vulnerabilities
Click here for a comprehensive library detailing device vulnerabilities.
Click the Submit a request button at the top right of the page