FTP: Defines the file transfer protocol, port 2 1.
Elnet: it is a port for remote login. Users can connect to the computer remotely as themselves. Through this port, communication service based on DOS mode can be provided. Port 23
SMTP: A simple mail transmission protocol is defined, and now many mail servers use it to send mail. Simple mail transfer protocol
POP3: corresponding to SMTP, POP3 is used to receive mail. 1 10 port
Commonly used UDP protocol ports are:
HTTP: This is the most commonly used protocol, which is usually called Hypertext Transfer Protocol. Hypertext transfer protocol
DNS: used for domain name resolution service, which is most used in Windows NT system. Port 53
SNMP: Simple network management protocol, used to manage network devices.
16 1 port
Service type default port
Echo 7 daytime 13
FTP 2 1
Telnet 23
SMTP 25
Time 37
Whois 43
DNS 53
Gopher 70
Finger 79
WWW 80
POP3 1 10
NNTP 1 19
IRC 194