Find and Close Open Ports

An open port is an active port that can receive data. A closed port is one that is not receiving or rejects data.  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 and the router as the main door.

A port number uses 16 bits, so it can have a value of 0 to 65535 decimal. 

Open ports can impact the confidentiality, integrity, availability, and security 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.
• Security Risk:  Unwanted access can find its way through existing routing devices. Any application on a device may request that the router opens a port on its behalf to contact an entity outside of your local network.

Find and Close Ports on Fing Desktop

Identify and close open ports to minimize network vulnerabilities.  You can use Fing to find open ports.  On Fing Desktop, select Tools >Router Vulnerabilities to find open ports. The Router Vulnerability page shows your open ports and your router configuration status.

To close an open port select the port by clicking on the box, and then select Close 1 port.

Find Open Ports Using Fing Mobile App

To find open ports on Fing Mobile, do this:

1. Open Fing Mobile.
2. Click the Tools tab in the bottom toolbar.
3. 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.
4. Click the blue Find open ports button.

Common Port Numbers

• 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)

Close Open Ports

It is not possible to close an open port from Fing mobile.  You need to connect to the router and activate NAT PMP or UPnP, or a 3rd party app developed for PC or mobile.

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