FTP
The service used over FTP is Filetransfer..!!
port 21 FTP port 25 E-mail SMTP port 80 web server HTTP port 110 E-mail POP3
That is FTP
The network protocol that uses port 21 is FTP (File Transfer Protocol). FTP is commonly used for transferring files between a client and a server on a computer network. Port 21 is specifically designated for FTP control connections. When a user initiates an FTP connection, the client connects to the server's port 21 to establish communication for sending and receiving files. It is important to note that FTP operates in two modes: active mode and passive mode, each using different ports for data transfer.
The protocol is FTP and the port number 21 conquerorthecomputer.blogspot.com
21 port - FTP (File Transfer Protocol) 25 port - SMTP (Simple Mail Transfer Protocol) 110 port - POP3 (Post Office Protocol used by email clients) 80 port - HTTP (World wide web Portocol) Services: port 21- FTP, port 25- Secure shell, Port 80- Web Server and port 110-Web Server Protocol: port 21-FTP, port 25- SSH, port 80- HTTP and port 110- POP2
TCP port 20 is used by FTP (File Transfer Protocol) for data transfer. FTP also uses port 21.
If you are refering to port 21 (networking) then it is the port used by the FTP process (File Transfer Protocol). The person may be referring to AspenTech ip.21 which is a process control historian. See related link.
The IMAP (Internet Message Access Protocol) email protocol usually uses port 143.
I think you virtual, go to ports, open task manager go to application running
What protocol is used by web servers and on which port ?
HTTP is the hyper text transfer protocol . The port used by HTTP is port 80 . The HTTP is the protocol of application layer.
The standard port numbers for the specified protocols are as follows: SMTP (Simple Mail Transfer Protocol) uses port 25, POP3 (Post Office Protocol version 3) uses port 110, IMAP4 (Internet Message Access Protocol version 4) uses port 143, RPC (Remote Procedure Call) commonly uses port 135, LDAP (Lightweight Directory Access Protocol) operates on port 389, and the Global Catalog service typically uses port 3268. These ports facilitate various email and directory services in network communications.