Representative well-known ports for TCP/UDP

Representative well-known port of TTCP

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 header

◆ TCP well-known port

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

 http://www.ietf.org/rfc/rfc1700.txt

port numberService nameexplanation
20ftp-dataFile Transfer [Default Data]
twenty oneFTPFile Transfer [Default Data]
twenty twosshSSH Remote Login Protocol
twenty threetelnetTelnet
twenty fivesmtpSimple Mail Transfer
53domainDomain Name Server
67bootpsBootstrap Protocol Server
68bootpcBootstrap Protocol Client
70gopherGopher
79fingerfinger
80www-httpWorld Wide Web HTTP
88kerberosKerberos
110pop3Post Office Protocol - Version 3
119nntpNetwork News Transfer Protocol
one two threentpNetwork Time Protocol
137netbios-nsNETBIOS Name Service
138netbios-dgmNETBIOS Datagram Service
139netbios-ssnNETBIOS Session Service
161snmpSNMP
162snmp trapSNMP TRAP
179bgpBorder Gateway Protocol
443httpshttp protocol over TLS/SSL
445microsoft-dsMicrosoft-DS
636ldapsldap protocol over TLS/SSL

Representative well-known port of UDP

◆ 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 header

◆UDP well-known port

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

 http://www.ietf.org/rfc/rfc1700.txt

port numberService nameexplanation
53domainDomain Name Server
67bootpsBootstrap Protocol Server
68bootpcBootstrap Protocol Client
69tftpTrivial File Transfer
88kerberosKerberos
one two threentpNetwork Time Protocol
137netbios-nsNETBIOS Name Service
138netbios-dgmNETBIOS Datagram Service
139netbios-ssnNETBIOS Session Service
161snmpSNMP
162snmp trapSNMP TRAP
213ipxIPX
445microsoft-dsMicrosoft-DS
520routerRIP
546dhcpv6-clientDHCPv6 Client
547dhcpv6-serverDHCPv6 Server
Well-known port for UDP