Common Ports and Protocols

Common TCP Ports:

• 21 - FTP - File Transfer Protocol

• 22 - SSH - Secure Shell

• 23 - Telnet

• 25 - SMTP - Simple Mail Transfer Protocol

• 53 - DNS - Domain Name System

• 80 - HTTP - Hyper Text Transfer Protocol

• 443 - HTTPS - Hyper Text Transfer Protocol Secure

• 110 - POP3 - Post Office Protocol

• 139/445 - SMB - Secure Message Block / Samba

• 143 - IMAP - Internet Message Access Protocol

• 389 - LDAP - Lightweight Direcotry Access Protocol (Both TCP and UDP)

• 990 - FTPS - FTP over TLS/SSL

• 3306 - MySQL

• 3389 - RDP - Remote Desktop Protocol

Common UDP Ports:

• 53 - DNS - Domain Name System

• 67/68 - DHCP - Dynamic Host Configuration Protocol

• 69 - TFTP - Trivial File Transfer Protocol

• 123 - NTP - Network Time Protocol

• 161 SNMP - Simple Network Management Protocol

*Note:* some ISPs(Comcast) block port 25(SMTP) for residential and some commercial by default so sometimes they will change it to Port 587.