Common Port Numbers

Common TCP/IP Protocols and Ports

Protocol TCP/UDP Port Number
File Transfer Protocol (FTP)

(RFC 959)

TCP 20/21
Secure Shell (SSH)

(RFC 4250-4256)

TCP 22
Telnet

(RFC 854)

TCP 23
Simple Mail Transfer Protocol (SMTP)

(RFC 5321)

TCP 25
Domain Name System (DNS)

(RFC 1034-1035)

TCP/UDP 53
Dynamic Host Configuration Protocol (DHCP)

(RFC 2131)

UDP 67/68
Trivial File Transfer Protocol (TFTP)

(RFC 1350)

UDP 69
Hypertext Transfer Protocol (HTTP)

(RFC 2616)

TCP 80
Post Office Protocol (POP) version 3

(RFC 1939)

TCP 110
Network Time Protocol (NTP)

(RFC 5905)

UDP 123
NetBIOS

(RFC 1001-1002)

TCP/UDP 137/138/139
Internet Message Access Protocol (IMAP)

(RFC 3501)

TCP 143
Simple Network Management Protocol (SNMP)

(RFC 1901-1908, 3411-3418)

TCP/UDP 161/162
Border Gateway Protocol (BGP)

(RFC 4271)

TCP 179
Lightweight Directory Access Protocol (LDAP)

(RFC 4510)

TCP/UDP 389
Hypertext Transfer Protocol over SSL/TLS (HTTPS)

(RFC 2818)

TCP 443
Lightweight Directory Access Protocol over TLS/SSL (LDAPS)

(RFC 4513)

TCP/UDP 636
FTP over TLS/SSL

(RFC 4217)

TCP 989/990
The complete list of assigned ports and their assigned services can be seen at http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xml.