CodeKeetCodeKeet

Port Number Reference

Complete reference of 89+ well-known TCP/UDP ports with services, protocols, and security notes. 100% client-side.

Well-known
0–1023
IANA assigned
Registered
1024–49151
Applications
Dynamic
49152–65535
Ephemeral
89 ports
21FTP ControlTCPWell-known★ Popular
FTP control channel
Use: File Transfer Protocol command channel.
⚠️
Security: Credentials sent in plaintext. Prefer SFTP/FTPS.
22SSHTCPWell-known★ Popular
Secure Shell — encrypted remote login
Use: Remote administration, Git over SSH, SCP/SFTP file transfer.
⚠️
Security: Frequently targeted by brute-force attacks. Use key auth, disable root login, consider changing port.
25SMTPTCPWell-known★ Popular
Simple Mail Transfer Protocol
Use: Server-to-server email relay.
⚠️
Security: Often blocked by ISPs to prevent spam. Use 587 for submission.
53DNSTCP/UDPWell-known★ Popular
Domain Name System
Use: Resolve domain names to IP addresses. UDP for queries, TCP for zone transfers and large responses.
⚠️
Security: Misconfigured DNS can be used in amplification DDoS attacks. Enable rate limiting.
80HTTPTCPWell-known★ Popular
Hypertext Transfer Protocol (unencrypted)
Use: Standard HTTP web traffic. Should redirect to HTTPS (443).
443HTTPSTCPWell-known★ Popular
HTTP over TLS/SSL (encrypted)
Use: Standard secure web traffic. All modern websites should use this.
445SMBTCPWell-known★ Popular
Server Message Block (Windows file sharing)
Use: Windows file sharing, printer sharing.
⚠️
Security: Target of WannaCry, EternalBlue. Block at internet edge.
587SMTP SubmissionTCPWell-known★ Popular
SMTP submission with STARTTLS
Use: Client-to-server email submission (modern standard).
993IMAPSTCPWell-known★ Popular
IMAP over SSL
Use: Secure email access (standard for modern clients).
3000Dev ServerTCPRegistered★ Popular
Common dev server port
Use: Next.js, React, Node.js, Rails dev servers.
3306MySQLTCPRegistered★ Popular
MySQL / MariaDB database server
Use: Default port for MySQL and MariaDB.
⚠️
Security: Never expose to the internet. Restrict to localhost or private network.
3389RDPTCPRegistered★ Popular
Remote Desktop Protocol (Windows)
Use: Remote GUI access to Windows machines.
⚠️
Security: Frequently targeted by ransomware. Restrict to VPN or IP allowlist.
5432PostgreSQLTCPRegistered★ Popular
PostgreSQL database server
Use: Default port for PostgreSQL.
⚠️
Security: Never expose to the internet. Use firewall rules.
6379RedisTCPRegistered★ Popular
Redis in-memory data store
Use: Cache, session storage, message broker.
⚠️
Security: No authentication by default. Frequently breached. Never expose to the internet.
8000HTTP AlternateTCPRegistered★ Popular
Common dev server port
Use: Python http.server, Django dev server, various development servers.
8080HTTP AlternateTCPRegistered★ Popular
Alternative HTTP port
Use: Often used for development servers, proxies, and Tomcat.
27017MongoDBTCPRegistered★ Popular
MongoDB database server
Use: Default port for MongoDB.
⚠️
Security: No authentication by default. Massive security risk. Never expose.
20FTP DataTCPWell-known
FTP data transfer
Use: Active FTP data channel.
⚠️
Security: FTP is unencrypted. Use SFTP (22) or FTPS instead.
23TelnetTCPWell-known
Telnet — unencrypted remote login
Use: Legacy remote access (obsolete).
⚠️
Security: Sends passwords in plaintext. Do not use. Disable on all modern systems.
67DHCP ServerUDPWell-known
Dynamic Host Configuration Protocol (server)
Use: Assigns IP addresses to devices on the network.
68DHCP ClientUDPWell-known
Dynamic Host Configuration Protocol (client)
Use: Requests IP addresses from DHCP servers.
69TFTPUDPWell-known
Trivial FTP
Use: Simple file transfer for firmware, PXE boot, network configs.
⚠️
Security: No authentication. Only use on trusted local networks.
110POP3TCPWell-known
Post Office Protocol v3
Use: Download email from server (legacy).
⚠️
Security: Unencrypted by default. Use POP3S (995) instead.
111rpcbindTCP/UDPWell-known
RPC port mapper
Use: Maps RPC program numbers to ports (NFS dependency).
⚠️
Security: Frequently scanned. Restrict access.
123NTPUDPWell-known
Network Time Protocol
Use: Synchronize system clocks across the network.
135MS RPCTCPWell-known
Microsoft RPC Endpoint Mapper
Use: Windows RPC services.
⚠️
Security: Target of remote exploits. Block at the perimeter.
137NetBIOS NameUDPWell-known
NetBIOS Name Service
Use: Windows name resolution (legacy).
138NetBIOS DatagramUDPWell-known
NetBIOS Datagram Service
Use: Windows name resolution (legacy).
139NetBIOSTCPWell-known
NetBIOS Session Service
Use: Legacy Windows file sharing.
⚠️
Security: Legacy protocol with known vulnerabilities.
143IMAPTCPWell-known
Internet Message Access Protocol
Use: Email access with server-side folders (legacy).
⚠️
Security: Unencrypted by default. Use IMAPS (993) instead.
161SNMPUDPWell-known
Simple Network Management Protocol
Use: Monitor and manage network devices (routers, switches).
⚠️
Security: Default community strings (public/private) are a security risk. Use SNMPv3.
162SNMP TrapUDPWell-known
SNMP Trap receiver
Use: Receives asynchronous SNMP notifications.
179BGPTCPWell-known
Border Gateway Protocol
Use: Internet routing between autonomous systems.
389LDAPTCP/UDPWell-known
Lightweight Directory Access Protocol
Use: Directory services (Active Directory, OpenLDAP).
⚠️
Security: Unencrypted by default. Use LDAPS (636).
465SMTPSTCPWell-known
SMTP over SSL (implicit TLS)
Use: Legacy secure SMTP (deprecated in favor of 587 + STARTTLS).
500IKE / IPsecUDPWell-known
Internet Key Exchange (IPsec VPN)
Use: IPsec VPN key negotiation.
512rexecTCPWell-known
Remote execution
Use: Legacy remote execution (obsolete).
⚠️
Security: Insecure. Disable.
513rloginTCPWell-known
Remote login
Use: Legacy remote login (obsolete).
⚠️
Security: Insecure. Use SSH instead.
514rsh / SyslogTCP/UDPWell-known
Remote shell / Syslog
Use: TCP: remote shell (legacy). UDP: syslog messages.
⚠️
Security: rsh is insecure. Use SSH. Syslog over UDP is unencrypted.
515LPDTCPWell-known
Line Printer Daemon
Use: Legacy Unix printing.
631IPPTCPWell-known
Internet Printing Protocol
Use: Network printing (CUPS).
636LDAPSTCPWell-known
LDAP over SSL/TLS
Use: Secure directory services.
873rsyncTCPWell-known
rsync file synchronization
Use: Efficient incremental file transfer and backup.
995POP3STCPWell-known
POP3 over SSL
Use: Secure POP3 email retrieval.
1080SOCKS ProxyTCPRegistered
SOCKS proxy
Use: SOCKS4/5 proxy for tunneling traffic.
1194OpenVPNTCP/UDPRegistered
OpenVPN
Use: VPN connections (commonly UDP).
1433MSSQLTCPRegistered
Microsoft SQL Server
Use: Default port for SQL Server.
⚠️
Security: Common target for attacks. Restrict access.
1521Oracle DBTCPRegistered
Oracle Database listener
Use: Oracle database connections.
1701L2TPUDPRegistered
Layer 2 Tunneling Protocol
Use: VPN tunneling (often with IPsec).
1723PPTPTCPRegistered
Point-to-Point Tunneling Protocol
Use: Legacy VPN (obsolete).
⚠️
Security: Broken encryption. Do not use. Use WireGuard or OpenVPN.
1812RADIUS AuthUDPRegistered
RADIUS authentication
Use: Network access authentication (WPA-Enterprise, VPNs).
1813RADIUS AcctUDPRegistered
RADIUS accounting
Use: RADIUS accounting and session tracking.
1883MQTTTCPRegistered
MQTT message broker
Use: IoT messaging protocol.
1900SSDPUDPRegistered
Simple Service Discovery Protocol
Use: UPnP device discovery (smart TVs, IoT).
⚠️
Security: Frequently abused in DDoS amplification attacks.
1900SSDPUDPRegistered
Simple Service Discovery Protocol
Use: UPnP device discovery.
2049NFSTCP/UDPRegistered
Network File System
Use: Unix/Linux file sharing over the network.
⚠️
Security: Often misconfigured. Restrict to trusted networks.
2181ZooKeeperTCPRegistered
Apache ZooKeeper
Use: Distributed configuration and coordination.
2375Docker APITCPRegistered
Docker daemon REST API (unencrypted)
Use: Remote Docker control.
⚠️
Security: No authentication by default. Exposes full host control. NEVER expose.
2376Docker API (TLS)TCPRegistered
Docker daemon REST API over TLS
Use: Secure remote Docker control.
2379etcd ClientTCPRegistered
etcd client API
Use: Kubernetes control-plane data store.
2380etcd PeerTCPRegistered
etcd peer communication
Use: Kubernetes etcd cluster communication.
3001GrafanaTCPRegistered
Grafana dashboard
Use: Metrics visualization (default port).
3478STUN/TURNTCP/UDPRegistered
STUN/TURN for WebRTC
Use: WebRTC NAT traversal and relay.
4000Dev ServerTCPRegistered
Common dev server port
Use: Phoenix, Gatsby, other Node.js dev servers.
4500IPsec NAT-TUDPRegistered
IPsec NAT Traversal
Use: IPsec VPN through NAT.
5000Dev ServerTCPRegistered
Common dev server port
Use: Flask, ASP.NET Core dev server, macOS AirPlay Receiver.
5060SIPTCP/UDPRegistered
Session Initiation Protocol
Use: VoIP signaling.
⚠️
Security: Commonly targeted for toll fraud.
5061SIP (TLS)TCPRegistered
SIP over TLS
Use: Secure VoIP signaling.
5173ViteTCPRegistered
Vite dev server default
Use: Vite/React/Vue dev server.
5222XMPP ClientTCPRegistered
XMPP client connections
Use: Jabber/chat messaging.
5269XMPP ServerTCPRegistered
XMPP server-to-server
Use: Federation between XMPP servers.
5349TURN (TLS)TCPRegistered
TURN over TLS
Use: Secure WebRTC relay.
5353mDNSUDPRegistered
Multicast DNS
Use: Zero-configuration networking (Bonjour, Avahi).
5353mDNSUDPRegistered
Multicast DNS
Use: Local network name resolution (Bonjour).
5601KibanaTCPRegistered
Kibana web UI
Use: Elasticsearch visualization.
5672AMQPTCPRegistered
Advanced Message Queuing Protocol
Use: RabbitMQ message broker.
5900VNCTCPRegistered
Virtual Network Computing
Use: Remote GUI access to Linux/Windows (cross-platform).
⚠️
Security: Often misconfigured without authentication. Never expose directly.
6443Kubernetes APITCPRegistered
Kubernetes API server
Use: kubectl and control-plane communication.
8443HTTPS AlternateTCPRegistered
Alternative HTTPS port
Use: Tomcat HTTPS, some admin panels.
8883MQTT (TLS)TCPRegistered
MQTT over TLS
Use: Secure IoT messaging.
9090PrometheusTCPRegistered
Prometheus server web UI
Use: Metrics collection and querying.
9093AlertmanagerTCPRegistered
Prometheus Alertmanager
Use: Alert handling for Prometheus.
9200ElasticsearchTCPRegistered
Elasticsearch REST API
Use: Search engine and analytics.
⚠️
Security: Often exposed without auth. Data leak risk. Restrict access.
9300Elasticsearch ClusterTCPRegistered
Elasticsearch inter-node communication
Use: Cluster communication between Elasticsearch nodes.
9339Google PlayTCPRegistered
Google Play services
Use: Android app store communication.
10250KubeletTCPRegistered
Kubernetes kubelet API
Use: Node-level operations in Kubernetes.
11211MemcachedTCP/UDPRegistered
Memcached caching system
Use: In-memory caching layer.
⚠️
Security: No authentication by default. Used in amplification DDoS attacks.
15672RabbitMQ MgmtTCPRegistered
RabbitMQ management UI
Use: RabbitMQ web dashboard.
51820WireGuardUDPDynamic
WireGuard VPN
Use: Modern, fast VPN protocol.

📖 Most Common Ports (Quick Reference)

🔒 100% private: Reference data is bundled locally. Based on IANA Service Name and Transport Protocol Port Number Registry.

About Port Number Reference

Network ports are 16-bit numbers (0–65535) that identify specific services or processes on a host. When a client connects to a server, it specifies both an IP address and a port. Ports are divided into three ranges: well-known ports (0–1023), registered ports (1024–49151), and dynamic/private ports (49152–65535). Certain ports are permanently assigned by IANA to specific services (80 for HTTP, 443 for HTTPS, 22 for SSH, 3306 for MySQL). Knowing which ports are commonly used — and which are security risks if exposed — is essential for firewall configuration, server hardening, and network troubleshooting. This reference lists the most important ports with their services, protocols, and security notes.

How It Works

  1. Search by port number (e.g., "443") or service name (e.g., "ssh").
  2. Filter by category (web, database, email, file transfer, security, etc.).
  3. Click any row for detailed info: protocol, description, common use.
  4. Danger ports (commonly attacked) are flagged with a ⚠️ warning.

✨ Key Features

  • ✓100+ well-known and registered ports
  • ✓Search by number or service name
  • ✓Filter by category (web, database, email, file, security, dev, other)
  • ✓TCP/UDP protocol indicator
  • ✓Service description and common use
  • ✓Security warnings for commonly-attacked ports
  • ✓Port range reference (well-known, registered, dynamic)
  • ✓RFC and IANA references
  • ✓One-click copy of port number
  • ✓100% client-side — no data sent to any server

🎯 Common Use Cases

  • →Configuring a firewall (which ports to open/close)
  • →Debugging "connection refused" errors
  • →Setting up a new server (what ports should be exposed)
  • →Hardening a production system (closing dangerous ports)
  • →Understanding a network scan (nmap output)
  • →Learning which service runs on which port
  • →Verifying that a custom port does not conflict with known services
  • →Checking the security posture of a cloud VM

💡 Advanced Tips & Pro Insights

  • ▸Well-known ports (0–1023) require root/admin privileges to bind on Unix systems. Use ports >1024 for user applications.
  • ▸Always prefer HTTPS (443) over HTTP (80). Port 80 should redirect to 443.
  • ▸Ports commonly attacked: 21 (FTP), 23 (Telnet), 135/137-139/445 (Windows SMB), 1433 (MSSQL), 3306 (MySQL), 3389 (RDP), 5432 (PostgreSQL), 6379 (Redis), 27017 (MongoDB). Never expose these directly to the internet without a firewall.
  • ▸Redis, MongoDB, and Elasticsearch have no authentication by default — exposing them is a critical security risk. Many cloud breaches come from open Redis/MongoDB ports.
  • ▸For remote access, prefer SSH (22) with key-based auth, or VPN, instead of RDP (3389) or VNC (5900).
  • ▸Use "nmap localhost" or "netstat -tuln" to see which ports your server is listening on.

Frequently Asked Questions

Is this port reference free?▾
Yes, this port number reference is completely free with no signup, email, or usage limits.
Is my data safe?▾
Yes, 100% safe. All lookups happen in your browser. Reference data is bundled locally. Nothing is sent to any server.
What is a network port?▾
A network port is a 16-bit number (0–65535) that identifies a specific service or process on a host. Combined with an IP address, it uniquely identifies a communication endpoint.
What are the port ranges?▾
Well-known ports: 0–1023 (assigned by IANA to common services). Registered ports: 1024–49151 (assigned for specific applications). Dynamic/private ports: 49152–65535 (ephemeral, assigned by the OS for client connections).
What is the difference between TCP and UDP ports?▾
TCP is connection-oriented (reliable, ordered). UDP is connectionless (fast, no guarantees). The same port number can be used by TCP and UDP independently — e.g., DNS uses both 53/tcp and 53/udp.
Which ports should I open on a web server?▾
For a typical web server: 22 (SSH, restricted to your IP), 80 (HTTP, redirect to HTTPS), 443 (HTTPS). Close everything else. Add 25/587 for email, or 3306 for MySQL only if accessed remotely (strongly discouraged).
Why is Telnet (port 23) dangerous?▾
Telnet sends data — including passwords — in plaintext. Anyone on the network can sniff credentials. Use SSH instead. Telnet should be disabled on any modern system.
What is an ephemeral port?▾
Ephemeral (dynamic) ports are temporary ports assigned by the OS when a client initiates an outgoing connection. They range from 49152–65535 on most systems. They are released after the connection closes.