Common port numbers
What runs on each well-known TCP and UDP port, whether it is safe to expose, and a one-click check for each. Select a port for its full page.
| Port | Service | Protocol | Expose? |
|---|---|---|---|
| 20 | FTP data File Transfer Protocol (data channel, active mode) | TCP | No |
| 21 | FTP File Transfer Protocol (control channel) | TCP | No |
| 22 | SSH Secure Shell (SSH, SFTP, SCP) | TCP | With care |
| 23 | Telnet Telnet remote terminal | TCP | No |
| 25 | SMTP Simple Mail Transfer Protocol (server-to-server relay) | TCP | With care |
| 53 | DNS Domain Name System | TCP/UDP | With care |
| 67 | DHCP server DHCP / BOOTP (server side) | UDP | With care |
| 68 | DHCP client DHCP / BOOTP (client side) | UDP | Yes |
| 69 | TFTP Trivial File Transfer Protocol | UDP | No |
| 80 | HTTP Hypertext Transfer Protocol | TCP | Yes |
| 110 | POP3 Post Office Protocol v3 | TCP | With care |
| 123 | NTP Network Time Protocol | UDP | With care |
| 135 | MS RPC Microsoft RPC endpoint mapper (DCOM) | TCP | No |
| 137 | NetBIOS name NetBIOS Name Service | UDP | No |
| 139 | NetBIOS session NetBIOS Session Service (SMB over NetBIOS) | TCP | No |
| 143 | IMAP Internet Message Access Protocol | TCP | With care |
| 161 | SNMP Simple Network Management Protocol | UDP | No |
| 162 | SNMP trap SNMP traps and notifications | UDP | With care |
| 389 | LDAP Lightweight Directory Access Protocol | TCP/UDP | No |
| 443 | HTTPS HTTP over TLS (and HTTP/3 over QUIC on UDP) | TCP/UDP | Yes |
| 445 | SMB Server Message Block (Windows file sharing) | TCP | No |
| 465 | SMTPS SMTP submission over implicit TLS | TCP | Yes |
| 514 | Syslog Syslog | UDP | With care |
| 587 | SMTP submission Mail submission (STARTTLS) | TCP | Yes |
| 636 | LDAPS LDAP over TLS | TCP | With care |
| 853 | DNS over TLS DNS over TLS (DoT) | TCP | Yes |
| 990 | FTPS FTP over implicit TLS | TCP | With care |
| 993 | IMAPS IMAP over TLS | TCP | Yes |
| 995 | POP3S POP3 over TLS | TCP | Yes |
| 1194 | OpenVPN OpenVPN | UDP | Yes |
| 1433 | MS SQL Microsoft SQL Server | TCP | No |
| 1521 | Oracle DB Oracle Database listener (TNS) | TCP | No |
| 1883 | MQTT MQTT (IoT messaging) | TCP | No |
| 2049 | NFS Network File System | TCP/UDP | No |
| 3000 | Dev server Common development / app port (Node.js, Grafana, Rails) | TCP | With care |
| 3306 | MySQL MySQL / MariaDB | TCP | No |
| 3389 | RDP Remote Desktop Protocol | TCP/UDP | No |
| 5000 | App / UPnP Flask dev server, Synology DSM, macOS AirPlay Receiver | TCP | With care |
| 5060 | SIP Session Initiation Protocol (VoIP) | TCP/UDP | No |
| 5432 | PostgreSQL PostgreSQL | TCP | No |
| 5900 | VNC Virtual Network Computing (remote desktop) | TCP | No |
| 6379 | Redis Redis | TCP | No |
| 8080 | HTTP alternate Alternate HTTP (proxies, Tomcat, Jenkins, dev servers) | TCP | With care |
| 8443 | HTTPS alternate Alternate HTTPS (admin panels, Tomcat, UniFi, Plesk) | TCP | With care |
| 9000 | App port PHP-FPM, Portainer, SonarQube, MinIO | TCP | With care |
| 25565 | Minecraft Minecraft: Java Edition server | TCP | Yes |
| 27015 | Steam / Source Steam game servers (Source engine: CS2, Garry's Mod, Rust) | TCP/UDP | Yes |
| 27017 | MongoDB MongoDB | TCP | No |
| 32400 | Plex Plex Media Server | TCP | Yes |
| 51820 | WireGuard WireGuard VPN | UDP | Yes |
Port ranges
- 0–1023, well-known: assigned by IANA to core protocols. On Linux and macOS, only root (or a process with CAP_NET_BIND_SERVICE) can listen on them.
- 1024–49151, registered: assigned on request to applications (3306 MySQL, 3389 RDP, 25565 Minecraft).
- 49152–65535, dynamic: never assigned; used for ephemeral client ports.
Assignments follow the IANA Service Name and Transport Protocol Port Number Registry; some entries (3000, 5000, 9000) are de-facto conventions rather than formal assignments, and are labelled as such on their pages.
Questions people ask
How many ports are there?
65,536 TCP ports and 65,536 UDP ports (0–65535) per IP address. IANA divides them into well-known (0–1023), registered (1024–49151) and dynamic/ephemeral (49152–65535) ranges.
What is the difference between TCP and UDP ports?
TCP ports carry connection-oriented traffic with a handshake, ordering and retransmission (web, SSH, mail). UDP ports carry connectionless datagrams (DNS queries, VoIP, games, WireGuard). TCP 53 and UDP 53 are separate ports that happen to share a number.
Which ports should never be open to the internet?
Database ports (1433, 3306, 5432, 6379, 27017), Windows file sharing and RPC (135, 139, 445), remote desktop (3389, 5900), Telnet (23) and SNMP (161). They are among the most scanned and exploited ports.
What are ephemeral ports?
The temporary source ports your OS picks for outgoing connections. Linux uses 32768–60999 by default; Windows and macOS use 49152–65535.