Table 1: Examples of Well-Known Ports

Port	Protocol Name	Description
13	UDP, TCP daytime	The time of day
20	TCP ftp-data	Data channel for FTP
21	TCP ftp-control	Control channel for FTP
23	TCP telnet		Telnet
25	TCP smtp		SMTP mail
37	UDP, TCP time	The time of day
43	TCP		whois
53	TCP		DNS
69	UDP		tftp
70	TCP		gopher
79	TCP		finger
80	TCP		http
88	UDP		kerberos
109	TCP		pop-2
110	TCP		pop-3
161	UDP		snmp
162	UDP		snmp-trap
517	UDP		talk
520	UDP		route
540	TCP		uucp