How to disable port 21 \ 23 \ 25 in Windows

Comments: Disable port 21 \ 23 \ 25 in Windows. Sometimes, to ensure security, we need to disable port 21 for FTP (File Transfer Protocol) services.

Port Description: port 21 is mainly used for the FTP (File Transfer Protocol) service. The FTP service is mainly used to upload and download files between two computers, one computer acts as the FTP client, and the other computer acts as the FTP server. you can log on to the FTP server using anonymous logon and authorized username and password logon. Currently, file transmission through the FTP service is the most important method for uploading and downloading files on the Internet. These servers have read/write directories. Hackers or Crackers use these servers as nodes that transmit warez (private programs) and pr0n (intentionally misspelled words to avoid being classified by search engines.

Disable port 21
1. Click Start> set> control, select administrative tools, and double-click open.



2. on the "Administrative Tools" Page, select "service" and double-click it.



3. In the service list in the "services" dialog box, find the FTP Hing service.



4. Right-click and select "properties ".



5. In the "FTP Publishing attributes" dialog box, change the Startup Type to "Manual ".



6. Click "stop" to change the service status to "stop" and click "OK" to complete the settings.

Port 23 is mainly used for the Telnet (Remote logon) service and is a common logon and simulation program on the Internet.
Port Description: port 23 is mainly used for the Telnet (Remote logon) service and is a common logon and simulation program on the Internet. You also need to set the client and server. The client that enables the Telnet service can log on to the remote Telnet server and use the authorized user name and password to log on. After logging on, you can use the Command Prompt window to perform corresponding operations. In Windows, you can type the "Telnet" command in the Command Prompt window to remotely log on using Telnet.

Suggestion: using the Telnet service, hackers can search for Unix services remotely and scan the operating system type. In addition, the Telnet service in Windows 2000 has multiple serious vulnerabilities, such as permission escalation and denial of service, which can cause remote server crash. Port 23 of the Telnet service is also the default port of the TTS (Tiny Telnet Server) Trojan. Therefore, we recommend that you disable port 23.

Disable port 23
1. Click Start> set> control, select administrative tools, and double-click open.



2. on the "Administrative Tools" Page, select "service" and double-click it.



3. In the service list of the "service" dialog box, find the Telnet service.



4. Right-click and select "properties ".



5. In the "Telnet properties" dialog box, change the Startup Type to "Manual ".



6. Click "stop" to change the service status to "stop" and click "OK" to complete the settings.

 
Port 25 is open to SMTP (Simple Mail Transfer Protocol, Simple Mail Transfer Protocol) servers and is mainly used to send emails. Currently, most Mail servers use this Protocol.
Port Description: port 25 is open to the SMTP (Simple Mail Transfer Protocol) server, which is mainly used to send emails. Currently, most Mail servers use this Protocol. For example, when using the e-mail client program, we need to enter the SMTP server address when creating an account. By default, this server address uses port 25.

Port vulnerabilities:
1. Using port 25, hackers can find SMTP servers to forward spam.
Port 2. 25 is opened by many Trojans, such as Ajan, Antigen, Email Password Sender, ProMail, trojan, Tapiras, Terminator, WinPC, and WinSpy. For WinSpy, open port 25 to monitor all windows and modules running on the computer.
Operation suggestion: if you do not want to set up an SMTP mail server, you can disable this port.

Disable port 25
1. Click Start> set> control, select administrative tools, and double-click open.



2. on the "Administrative Tools" Page, select "service" and double-click it.



3. In the service list of the "service" dialog box, find the Simple Mail Transport Protocol (SMTP) Service.



4. Right-click and select "properties ".



5. In the "Simple Mail Transport Protocol (SMTP) attributes" dialog box, change the Startup Type to "Manual ".



6. Click "stop" to change the service status to "stop" and click "OK" to complete the settings.