Port Numbers

most important port numbers from A+, Network+, and Security+

Port 21 over TCP

File Transfer Protocol (FTP) - Control

Port 23 over TCP

Telnet

Port 143 over TCP

IMAP - Internet Mail Access Protocol

Port 25 over TCP

SMTP - Simple Mail Transfer Protocol

Port 110 over TCP

POP - Post Office Protocol

Port 587

SMTPS (Secure)

Port 995 over TCP

POP3

Ports 137-139 (TCP/UDP)

NetBIOS over TCP/IP

Port 3389 over TCP

Remote Desktop Protocol (RDP)

Port 445 over TCP

Server Message Block (SMB)

Port 22 over TCP

Secure Shell (SSH)

Port 443 over TCP

HTTPS

Port 993 over TCP

IMAP Secure (IMAPS)

Port 20 over TCP

File Transfer Protocol (FTP) - Data

Port 68 over UDP

Dynamic Host Configuration Protocol (DHCP) - Client

Port 389 over TCP

Lightweight Directory Access Protocol (LDAP)

Port 53 over TCP/UDP

Domain Name System (DNS)

Port 80 over TCP

HTTP

Port 636 over TCP/IP

LDAP Secure

Port 514 over UDP

Syslog

Port 3306 over TCP

MySQL/MariaDB

Port 5060 over TCP/UDP

Session Initiation Protocol

Port 853 over TCP

DNS over transport layer security (DoT)

Port 123 over UDP

Network Time Protocol (NTP)

Port 465 over TCP

SMPTS (mostly deprecated)

Port 49 over TCP/UDP

TACACS+

Port 500 over UDP

IPSec/IKE

Port 1812-1813 over TCP/UDP

RADIUS