Services and ports that are commonly used under Windows

Because the service is too many, so the corresponding port is also many, here only some of the commonly used services and the corresponding port to do a simple description, the order is small to large arrangement, each of the "Port type: Port number" in the form of the beginning (such as: "tcp:10000").

TCP20: Dedicated to FTP data transfer, active mode (port) (FTP transfer mode see schematic FTP active mode vs. passive mode and client settings, FTP server uses TCP20 port to actively connect to the client for data transfer.)

TCP21: Dedicated to FTP Message control, in the FTP service, the client uses the passive mode (PASV) connection to the FTP server, the server will first connect to the TCP21 port to negotiate, the negotiated content including the server to open which port for data transmission, if the client uses active mode , the client tells the server to open which port itself to wait for the FTP server to connect with the TCP20 port for data transfer.

TCP22: For SSH (secure Shell) connection, SSH connection is much more secure than Telnet, which is the default open TCP22 port for remote management of the system.

TCP23: Is the port used by Telnet, in the Windows command prompt to use the "telnet+ Server ip+ Port" way to enter the port corresponding to the remote host, for example, Telnet pop.qq.com 110 Port After you can enter the corresponding command to operate the mail in the mailbox, this command is often used to test whether the host open the corresponding port, if not a meeting to indicate that the connection failed.

TCP25: Dedicated to the SMTP service, that is, for the purpose of transmitting mail, the client sends the message and the server forwards the message sends the data to the TCP25 port of the remote host.

The Udp53:dns server opens this port to provide domain name resolution services for clients.

TCP80: This does not need to be introduced, it is necessary to add that you can use other custom ports to provide Web services, such as in IIS, you can set different ports to distinguish between different sites, but need to be in the back of the port to add.

TCP110: For POP3 services, frequently used outlook and Foxmail are typically connected to the TCP110 port of the mail server to receive letters.

TCP135: For Remote Procedure call (RPC), can find remote Procedure calls (RPC) in the list of services, see its dependencies, you can see that n multiple services rely on this service, the importance imaginable.

TCP139: For Windows file and printer sharing, when copying shared files, it is the random port of the machine and the other's TCP139 port to establish a connection to transfer data.

TCP143: For IMAP services, IMAP is used to receive mail, and IMAP offers richer functionality than POP3.

TCP389:LADP protocol (Lightweight Directory Access Protocol) port, the Windows domain environment is based on the LDAP protocol architecture, the user information is stored in the Active Directory, the application can connect to the server's TCP389 port to obtain user information, Mail software, for example, can get a list of messages saved in the Active Directory by connecting to the Active Directory.

TCP443: Used for HTTPS (encrypted HTTP connection), this is a lot of places, such as the use of Internet banking to query bank account information is provided by the HTTPS connection.

TCP995: For encrypted POP3 connection, when the mail client set up Gmail mailbox must check "This server requires encrypted connection (SSL)" After the receiving server (POP3), and then the port will automatically become 995,

TCP3389 Port: For Remote Desktop Connection service, open Remote Desktop Connection under Windwos XP first to start the Remotes Desktop Services service, then right click on My Computer, select Properties, switch to remote options, Then tick allow users to connect remotely to this computer under Remote Desktop, by default the system administrator user has the right to telnet.

said above are some of the common ports, in fact, many of the default ports can be changed, such as the Web 80 port, in IIS or Apache can be modified; Remote Desktop Connection 3389 can be modified in the registry, system restart effective