Port 0: Reserved
Port 7: Echo
Port 13: Daytime
Port 20: FTP-Data (FTP data transfer)
Port 21: FTP (FTP control)
Port 22: SSH (Secure Shell)
Port 23: Telnet
Port 25: SMTP (Simple Mail Transfer Protocol)
Port 37: TIME (Time Protocol)
Port 42: Host Name Server
Port 43: WHOIS
Port 49: TACACS (Terminal Access Controller Access-Control System)
Port 53: DNS (Domain Name System)
Port 67: BOOTPS (Bootstrap Protocol Server)
Port 68: BOOTPC (Bootstrap Protocol Client)
Port 69: TFTP (Trivial File Transfer Protocol)
Port 70: Gopher
Port 79: Finger
Port 80: HTTP (HyperText Transfer Protocol)
Port 88: Kerberos
Port 101: HOSTNAME (NIC Host Name Server)
Port 102: ISO-TSAP (ISO Transport Service on top of TCP)
Port 110: POP3 (Post Office Protocol)
Port 113: Ident (Identification Protocol)
Port 119: NNTP (Network News Transfer Protocol)
Port 123: NTP (Network Time Protocol)
Port 135: MS RPC (Microsoft Remote Procedure Call)
Port 137: NetBIOS-NS (NetBIOS Name Service)
Port 138: NetBIOS-DGM (NetBIOS Datagram Service)
Port 139: NetBIOS-SSN (NetBIOS Session Service)
Port 143: IMAP (Internet Message Access Protocol)
Port 161: SNMP (Simple Network Management Protocol)
Port 162: SNMPTRAP (SNMP Trap)
Port 179: BGP (Border Gateway Protocol)
Port 194: IRC (Internet Relay Chat)
Port 201: AppleTalk Routing Maintenance
Port 389: LDAP (Lightweight Directory Access Protocol)
Port 443: HTTPS (HTTP Secure)
Port 445: SMB (Server Message Block over TCP)
Port 465: SMTPS (SMTP over SSL)
Port 512: exec (Remote Process Execution)
Port 513: login (Remote Login)
Port 514: shell/cmd (CMD like exec, but automatic login)
Port 515: LPD/LPR (Line Printer Daemon)
Port 520: RIP (Routing Information Protocol)
Port 546: DHCPv6-Client
Port 547: DHCPv6-Server
Port 554: RTSP (Real-Time Stream Control Protocol)
Port 587: Submission (Mail message submission)
Port 631: IPP (Internet Printing Protocol)
Port 636: LDAPS (LDAP over SSL)
Port 666: DOOM (Doom, first online multiplayer game)
Port 674: ACAP (Application Configuration Access Protocol)
Port 691: MS Exchange Routing
Port 700: EPP (Extensible Provisioning Protocol)
Port 873: rsync
Port 990: FTPS (FTP over SSL)
Port 993: IMAPS (IMAP over SSL)
Port 995: POP3S (POP3 over SSL)
Note that this list is not exhaustive but it covers many of the most commonly used well-known ports. The ports can also be used for different services based on specific configurations.
Port 1080: SOCKS proxy
Port 1194: OpenVPN
Port 1433-1434: Microsoft SQL Server
Port 1701: L2TP (Layer 2 Tunneling Protocol)
Port 1723: PPTP (Point-to-Point Tunneling Protocol)
Port 3306: MySQL
Port 3389: RDP (Remote Desktop Protocol)
Port 5060 & 5061: SIP (Session Initiation Protocol) – VoIP calls
Port 5190: AIM (AOL Instant Messenger)
Port 5222 & 5223: XMPP/Jabber – Instant messaging
Port 5432: PostgreSQL
Port 5900: VNC (Virtual Network Computing) – Remote desktop
Port 8080: HTTP alternate – Often used for web proxies
Dynamic or private ports in the range 49152-65535 are generally not assigned for specific services by the Internet Assigned Numbers Authority (IANA). These ports are used on an as-needed basis for ephemeral or temporary purposes by applications and services.
Here's how they typically work:
Ephemeral Ports: These ports are temporarily allocated for client-side sessions when communicating with a well-known port on a server. For example, if you visit a website, your browser might use one of these dynamic ports to connect to the well-known HTTP port (80) on the web server.
Application-Specific Ports: Some applications may choose to use a port within this range for specific, proprietary communication. This use is often documented in the application's own documentation but is not globally recognized or standardized.
Testing and Development: Many developers use these ports to avoid conflicts with well-known or registered ports when testing new applications or services.
Randomized Ports: Some security measures involve randomizing the ports used for outgoing connections to make it harder to track or interfere with a service.
Peer-to-Peer Communication: Some peer-to-peer (P2P) applications may use dynamic or private ports for direct communication between clients.
Because these ports are not standardized for specific services, there isn't an exhaustive list describing what each port in this range does. Their functionality is often determined by the specific applications that use them, and those applications could potentially use any port in this range for any purpose they see fit.
So, unlike the well-known and registered ports, the use of dynamic or private ports is largely determined by the application developers or the end-users themselves.