Roles, vulnerabilities, and Operation suggestions of TCP ports

When surfing the internet, we often see the word "Port" and often use the port number. For example, if "21" is added after the FTP address, "21" indicates the port number. So what does port mean? How can I view the port number? Does a port become the door to malicious cyberattacks ?, How should we face all kinds of ports? The following content will be introduced for your reference.



Port Introduction: This article introduces the concept and classification of ports and how to disable/enable a port.

Port 21: port 21 is mainly used for FTP (File Transfer Protocol) services.

Port 23: port 23 is mainly used for Telnet (Remote logon) services and is a common logon and simulation program on the Internet.

Port 25: port 25 is open to SMTP (Simple Mail Transfer Protocol) servers and is mainly used to send emails. Most Mail servers use this Protocol today.

Port 53: port 53 is open to DNS (Domain Name Server) servers and is mainly used for Domain Name resolution. DNS is the most widely used in the NT System.

Port 67, port 68: port 67, and port 68 are opened for the Bootstrap Protocol Server and Bootstrap Protocol Client of The Bootp service respectively.

Port 69: TFTP is a simple file transfer protocol developed by Cisco, similar to FTP.

Port 79: port 79 is open for the Finger service. It is mainly used to query details of users such as online users of remote hosts, operating system types, and whether a buffer overflow occurs.

Port 80: Port 80 is open for HTTP (HyperText Transport Protocol, HyperText Transfer Protocol), which is the most widely used Protocol for surfing the Internet. It is mainly used in WWW (World Wide Web, World Wide Web) the Protocol for transmitting information on the service.

Port 99: port 99 is used for a service named "metemedirelay" (sub-countermeasure delay). This service is rare and generally unavailable.

Port 109 and port 110: Port 109 is open for the POP2 (Post Office Protocol Version 2, Post Office Protocol 2) service, and port 110 is open for the POP3 (mail Protocol 3) service, POP2 and POP3 are mainly used to receive emails.

Port 111: port 111 is the port opened by SUN's Remote Procedure Call service. It is mainly used for internal process communication between different computers in a distributed system, RPC is an important component in a variety of network services.

Port 113: port 113 is mainly used for Authentication Service in Windows ).

Port 119: port 119 is open for "Network News Transfer Protocol" (NNTP.

Port 135: port 135 is mainly used to use the Remote Procedure Call Protocol and provide the DCOM (Distributed Component Object Model) service.

Port 137: port 137 is mainly used for "NetBIOS Name Service" (NetBIOS Name Service ).

Port 139: port 139 is provided for "NetBIOS Session Service" and is mainly used to provide Windows file and printer sharing and Samba Service in Unix.

Port 143: port 143 is mainly used for "Internet Message Access Protocol" v2 (Internet Message Access Protocol (IMAP ).

Port 161: port 161 is used for "Simple Network Management Protocol" (SNMP ).

Port 443: Port 43 is the Web browsing port, which is mainly used for HTTPS services. It is another type of HTTP that provides encryption and transmission through secure ports.

Html "> port 554: port 554 is used by default for" Real Time Streaming Protocol "(RTSP ).

Port 1024: Port 1024 is generally not allocated to a service. It is interpreted as "Reserved" in English ).

Port 1080: port 1080 is the port used by the Socks proxy service. The WWW Service is usually used by the Internet.

Port 1755: port 1755 is used by default for Microsoft Media Server (MMS ).

Port 4000: port 4000 is a commonly used QQ token tool. In other words, it is a port opened for the QQ client. The port used by the QQ server is port 8000.

Port 5554: In April 30 this year, it was reported that there was a new Worm against the Microsoft lsass Service-Worm. (Sasser), the virus can use TCP port 5554 to enable an FTP service, which is mainly used for virus propagation.

Port 5632: Port 5632 is the port opened by the remote control software pcAnywhere.

Port 8080: port 8080 is the same as port 80. It is used for WWW Proxy Service and can be browsed on the webpage.