Representative well-known ports for TCP/UDP

2022年9月23日 2022年9月23日

puchi-engineer

Here, we introduce typical TCP well-known ports.

First, let’s check the TCP header. You can see that the header has a source port number and a destination port number.

◆ TCP header

◆ TCP well-known port

Here are some well-known ports of TCP. Please refer to RFC1700 for details.

port number	Service name	explanation
20	ftp-data	File Transfer [Default Data]
twenty one	FTP	File Transfer [Default Data]
twenty two	ssh	SSH Remote Login Protocol
twenty three	telnet	Telnet
twenty five	smtp	Simple Mail Transfer
53	domain	Domain Name Server
67	bootps	Bootstrap Protocol Server
68	bootpc	Bootstrap Protocol Client
70	gopher	Gopher
79	finger	finger
80	www-http	World Wide Web HTTP
88	kerberos	Kerberos
110	pop3	Post Office Protocol – Version 3
119	nntp	Network News Transfer Protocol
one two three	ntp	Network Time Protocol
137	netbios-ns	NETBIOS Name Service
138	netbios-dgm	NETBIOS Datagram Service
139	netbios-ssn	NETBIOS Session Service
161	snmp	SNMP
162	snmp trap	SNMP TRAP
179	bgp	Border Gateway Protocol
443	https	http protocol over TLS/SSL
445	microsoft-ds	Microsoft-DS
636	ldaps	ldap protocol over TLS/SSL

◆ Representative well-known port of UDP

Here, we introduce typical UDP well-known ports.

First, let’s check the UDP header. You can see that the header has a source port number and a destination port number.

◆UDP header

◆UDP well-known port

Here are some well-known ports for UDP. Please refer to RFC1700 for details.

Well-known port for UDP