Common TCP/IP Port Numbers

My students often ask about the common TCP/IP port numbers that they need to know for Microsoft certification exams. A lot depends on the exam you are taking. For example, for Active Directory exam it will be helpful to know the ports that Active Directory uses.

Common TCP/IP Port Numbers

In general, here are some of the common TCP/IP port  numbers that are good to know. For a more detailed list download the PDF document TCP/IP Port Numbers.

TCP 20 FTP (File Transfer Protocol – Data)

TCP 21 FTP (File Transfer Protocol – Control)

TCP 22 SSH (Secure Shell – Remote login protocol)

TCP 23 Telnet

TCP 25 SMTP (Simple Mail Transfer Protocol)

TCP 53 DNS (Domain Name System)

TCP 67 BOOTPS (Bootstrap Protocol Server)

TCP 68 BOOTPC (Bootstrap Protocol Client)

TCP 80 HTTP (HyperText Transport Protocol)

TCP 88 Kerberos

TCO 110 POP3 (Post Office Protocol 3)

TCP 119 NNTP (Network News Transfer Protocol)

TCP 123 NTP (Network Time Protocol)

TCP 137 NetBIOS (NETBIOS Name Service)

TCP 138 NetBIOS (NETBIOS Datagram Service)

TCP 139 NetBIOS (NETBIOS Session Service)

TCP 143 IMAP (Internet Mail Access Protocol)

TCP 161 SNMP (Simple Network Management Protocol)

TCP 389 LDAP (Lightweight Directory Access Protocol)

TCP 443 HTTPS (HTTP secure – used for SSL)

Additional Resources:

IANA-Assigned Service Name and Port Numbers Registry

IANA IPv4 Address Space Registry