- Well-known/System Ports
- 0-1023
- User Ports/Registered Ports
- 1024-49151
- Dynamic/Private/Ephemeral Ports
- 49152-65535
- Port Numbers and their Applications
- 20 – FTP (Send file data)
- 21 – FTP (Session info)
- 22 – SSH, FTPS, SCP
- 23 – Telnet
- 25 – SMTP
- 49 – TACACS+
- 53 UDP/TCP – DNS
- 67 UDP – DHCP and BOOTP
- 69 – TFTP
- 80 – HTTP
- 88 – Kerberos
- 110 – POP3
- 119 – NNTP (Network News Transfer Protocol)
- 123 – NTP (Network Time Protocol)
- 137,138,139 – NetBIOS
- 143 – IMAP
- 161 – SNMP (Agents receive requests)
- 162 – SNMP (Controller receives data)
- 389 – TCP – LDAP Lightweight Directory Access – 389
- 443 – HTTPS (over TLS/SSL)
- 443 – SSTP (Over TLS/SSL) Secure Socket Tunneling Protocol
- 445 – SMB Server Messaging Block – 445
- 465 – SMTP Secure Mail Transfer Protocol
- 500 – IKE Internet Key Exchange
- 636 – LDAPS w/ TLS
- 989/990 – FTPS
- 1701 – L2TP, L2F Layer 2 Tunneling Protocol – 1701
- 1720 – H.323
- 1723 – PPTP Point to Point Transfer Protocol – 1723
- 1812,1813 – RADIUS RADIUS – 1813,1812
- 2427 – MGCP Media Gateway Control Protocol – 2427
- 2727 – MGCP
- 3389 – RDP Remote Desktop Protocol – 3389
- 5004 – RTP Real-time Transport Protocol – 5004
- 5005 – RTP (Default)
- 5060 – SIP (unencrypted) Session Initiation Protocol – 5060
- 5061 – SIP (encrypted with TLS)
- Protocol IDs
- PID 50 – ESP IPsec IPsec
- PID 51 – AH IPsec Authentication Headers