Networking Protocols and Well-Known TCP/UDP Ports

Port 20/21 (TCP)

FTP (File Transfer Protocol)

Port 22 (TCP)

SSH (Secure Shell) / SFTP

Port 23 (TCP)

Telnet

Port 25 (TCP)

SMTP (Simple Mail Transfer Protocol)

Port 53 (TCP/UDP)

DNS (Domain Name System)

Port 67/68 (UDP)

DHCP (Dynamic Host Configuration Protocol)

Port 69 (UDP)

TFTP (Trivial File Transfer Protocol)

Port 80 (TCP)

HTTP (Hypertext Transfer Protocol)

Port 88 (TCP/UDP)

Kerberos

Port 110 (TCP)

POP3 (Post Office Protocol v3)

Port 123 (UDP)

NTP (Network Time Protocol)

Port 143 (TCP)

IMAP (Internet Message Access Protocol)

Port 161/162 (UDP)

SNMP (Simple Network Management Protocol)

Port 389 (TCP/UDP)

LDAP (Lightweight Directory Access Protocol)

Port 443 (TCP)

HTTPS (HTTP Secure)

Port 445 (TCP)

SMB (Server Message Block)

Port 514 (UDP)

Syslog

Port 636 (TCP/UDP)

LDAPS (LDAP Secure)

Port 1433 (TCP)

Microsoft SQL Server

Port 1521 (TCP)

Oracle Database

Port 3389 (TCP/UDP)

RDP (Remote Desktop Protocol)

Port 5060/5061 (TCP/UDP)

SIP (Session Initiation Protocol)