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Port Reference
portstcpudpservicesnetworkingsecurityreference
Updated May 4, 2026
A comprehensive reference for well-known and commonly used network ports. Filter by protocol (TCP/UDP), category (Web, Database, VPN, Containers, etc.), or search by port number, service name, or description.
Includes 80+ ports across 13 categories with plain-English descriptions and exposure ratings (High/Medium) flagging ports that should not be directly internet-facing or use plaintext protocols. Quick lookup by number with context about what the port is used for.
Quick port lookup
76 ports
| Port | Protocol | Service | Category | Description | Exposure |
|---|---|---|---|---|---|
80 | TCP | HTTP | Web | Hypertext Transfer Protocol — unencrypted web traffic | — |
443 | TCP | HTTPS | Web | HTTP over TLS/SSL — encrypted web traffic | — |
8080 | TCP | HTTP-Alt | Web | Common HTTP alternate port — dev servers, proxies, Tomcat | — |
8443 | TCP | HTTPS-Alt | Web | Common HTTPS alternate port | — |
8888 | TCP | HTTP-Dev | Web | Jupyter Notebook default; various HTTP dev servers | — |
3000 | TCP | HTTP-Dev | Web | Node.js / React / Next.js dev servers | — |
4200 | TCP | HTTP-Dev | Web | Angular CLI dev server default | — |
5000 | TCP | HTTP-Dev | Web | Flask / various dev HTTP servers | — |
53 | TCP/UDP | DNS | DNS | Domain Name System — name resolution | — |
853 | TCP | DNS-over-TLS | DNS | DNS over TLS (DoT) — encrypted DNS queries | — |
5353 | UDP | mDNS | DNS | Multicast DNS — local network discovery (Bonjour/Avahi) | — |
25 | TCP | SMTP | Simple Mail Transfer Protocol — server-to-server email relay | high | |
465 | TCP | SMTPS | SMTP over SSL — legacy implicit TLS | — | |
587 | TCP | SMTP-Submission | SMTP message submission — STARTTLS preferred | — | |
110 | TCP | POP3 | Post Office Protocol v3 — email retrieval (plaintext) | medium | |
995 | TCP | POP3S | POP3 over SSL/TLS | — | |
143 | TCP | IMAP | Internet Message Access Protocol — email access (plaintext) | medium | |
993 | TCP | IMAPS | IMAP over SSL/TLS | — | |
20 | TCP | FTP-Data | File Transfer | FTP data transfer — active mode | high |
21 | TCP | FTP | File Transfer | FTP control — unencrypted file transfer | high |
22 | TCP | SSH / SFTP | Remote Access | Secure Shell + SFTP — encrypted remote access and file transfer | — |
69 | UDP | TFTP | File Transfer | Trivial File Transfer Protocol — diskless boot, firmware updates | medium |
989 | TCP | FTPS-Data | File Transfer | FTP over TLS — data channel | — |
990 | TCP | FTPS | File Transfer | FTP over TLS — control channel | — |
23 | TCP | Telnet | Remote Access | Unencrypted remote terminal — avoid; use SSH instead | high |
3389 | TCP | RDP | Remote Access | Remote Desktop Protocol — Windows remote desktop | medium |
5900 | TCP | VNC | Remote Access | Virtual Network Computing — screen sharing | medium |
5938 | TCP | TeamViewer | Remote Access | TeamViewer remote access | — |
1433 | TCP | MSSQL | Database | Microsoft SQL Server | high |
1521 | TCP | Oracle DB | Database | Oracle Database listener | high |
3306 | TCP | MySQL | Database | MySQL / MariaDB database | high |
5432 | TCP | PostgreSQL | Database | PostgreSQL relational database | high |
6379 | TCP | Redis | Database | Redis in-memory data store — no auth by default! | high |
27017 | TCP | MongoDB | Database | MongoDB document database | high |
9200 | TCP | Elasticsearch | Database | Elasticsearch REST API | high |
5984 | TCP | CouchDB | Database | Apache CouchDB HTTP API | — |
8086 | TCP | InfluxDB | Database | InfluxDB time-series HTTP API | — |
67 | UDP | DHCP-Server | Networking | DHCP server — IP address assignment | — |
68 | UDP | DHCP-Client | Networking | DHCP client — receives IP configuration | — |
123 | UDP | NTP | Networking | Network Time Protocol — time synchronization | — |
161 | UDP | SNMP | Networking | Simple Network Management Protocol — monitoring | medium |
162 | UDP | SNMP-Trap | Networking | SNMP trap notifications | — |
179 | TCP | BGP | Networking | Border Gateway Protocol — internet routing | — |
514 | UDP | Syslog | Networking | Unix syslog — system logging | — |
636 | TCP | LDAPS | Networking | LDAP over SSL — directory services | — |
389 | TCP | LDAP | Networking | Lightweight Directory Access Protocol (plaintext) | medium |
88 | TCP/UDP | Kerberos | Networking | Kerberos authentication protocol | — |
445 | TCP | SMB | Networking | Server Message Block — Windows file sharing; common attack surface | high |
139 | TCP | NetBIOS-SSN | Networking | NetBIOS Session Service — legacy Windows networking | high |
137 | UDP | NetBIOS-NS | Networking | NetBIOS Name Service | medium |
500 | UDP | IKE / IPsec | VPN | IKE key exchange — IPsec VPN phase 1 | — |
4500 | UDP | IPsec NAT-T | VPN | IPsec NAT traversal (UDP encapsulation) | — |
1194 | TCP/UDP | OpenVPN | VPN | OpenVPN — TLS-based VPN | — |
51820 | UDP | WireGuard | VPN | WireGuard — modern UDP VPN protocol | — |
1723 | TCP | PPTP | VPN | Point-to-Point Tunneling Protocol — deprecated, insecure | high |
1701 | UDP | L2TP | VPN | Layer 2 Tunneling Protocol — typically used with IPsec | — |
5672 | TCP | AMQP | Messaging | Advanced Message Queuing Protocol — RabbitMQ default | — |
5671 | TCP | AMQPS | Messaging | AMQP over TLS | — |
9092 | TCP | Kafka | Messaging | Apache Kafka broker | — |
1883 | TCP | MQTT | Messaging | Message Queuing Telemetry Transport — IoT messaging | — |
8883 | TCP | MQTT TLS | Messaging | MQTT over TLS | — |
2376 | TCP | Docker TLS | Containers | Docker daemon with TLS | — |
2377 | TCP | Docker Swarm | Containers | Docker Swarm cluster management | — |
6443 | TCP | Kubernetes API | Containers | Kubernetes API server | — |
10250 | TCP | kubelet API | Containers | Kubernetes kubelet HTTPS API | — |
2379 | TCP | etcd | Containers | etcd distributed key-value store client port | — |
2380 | TCP | etcd Peer | Containers | etcd peer-to-peer communication | — |
9090 | TCP | Prometheus | Monitoring | Prometheus metrics server | — |
3100 | TCP | Loki | Monitoring | Grafana Loki log aggregation | — |
3000 | TCP | Grafana | Monitoring | Grafana dashboard (also common for Next.js dev) | — |
9411 | TCP | Zipkin | Monitoring | Zipkin distributed tracing | — |
14268 | TCP | Jaeger | Monitoring | Jaeger distributed tracing HTTP | — |
111 | TCP/UDP | RPC / portmap | Misc | ONC RPC portmapper — required for NFS | medium |
2049 | TCP/UDP | NFS | Misc | Network File System | medium |
873 | TCP | rsync | Misc | rsync file synchronisation daemon | — |
11211 | TCP/UDP | Memcached | Misc | Memcached distributed cache — no auth by default! | high |
Notes on exposure ratings
- High — Should not be directly internet-facing; authenticate before exposing internally
- Medium — Plaintext or known vulnerabilities; prefer encrypted alternatives
- No rating — standard or encrypted protocol with reasonable defaults