Cheatsheet of well-known TCP/UDP ports for web, mail, database, directory, and operations services.
Common TCP and UDP ports for web, mail, database, directory, and operations services. Each row lists the port, the service, and its purpose. Use it to recognize traffic, configure firewalls, or pick a port for a new service.
Reference table · 53 entries
Common Network PortsExplained
53 of 53 rows
Web
HTTP
Carries unencrypted web traffic. The baseline protocol of the web.
HTTPS
Wraps HTTP in TLS. Carries encrypted web traffic.
Node.js
Serves Node.js dev servers by default. The default port for Express, React, and Next.js.
HTTP
Serves Django and Python dev servers by default. Also a common alternate HTTP port.
HTTP
Serves HTTP on a non-privileged port. Used for proxies and dev servers.
HTTPS
Serves HTTPS on a non-privileged port. Used for alternate TLS services.
Mail
SMTP
Relays mail between servers. Plain-text by default.
POP3
Retrieves mail from a mailbox. Plain-text POP3 without TLS.
NNTP
Transfers Usenet news articles between servers and readers. Plain-text by default.
IMAP
Syncs mailboxes with IMAP. Plain-text without TLS.
SMTPS
Carries SMTP over implicit TLS. Deprecated but still used.
SMTP
Accepts outbound mail from authenticated clients. The modern submission port.
IMAPS
Syncs mailboxes over TLS. Encrypted IMAP access.
POP3S
Retrieves mail over TLS. Encrypted POP3 access.
Database
MSSQL
Serves Microsoft SQL Server connections over TCP.
Oracle DB
Serves Oracle Database connections over TCP.
MySQL
Serves MySQL and MariaDB connections over TCP.
PostgreSQL
Serves PostgreSQL connections over TCP.
AMQP
Carries AMQP messages for RabbitMQ and other message brokers.
CouchDB
Exposes the CouchDB REST API over HTTP.
Redis
Serves Redis in-memory data store connections.
ClickHouse
Exposes the ClickHouse HTTP interface for queries.
Elasticsearch
Exposes the Elasticsearch REST API for indexing and search.
Memcached
Serves Memcached in-memory cache connections.
RabbitMQ
Serves the RabbitMQ management console over HTTP.
MongoDB
Serves MongoDB instance connections over TCP.
Directory & identity
Kerberos
Issues and validates authentication tickets. The core protocol for Active Directory logins.
LDAP
Carries LDAP directory queries. Plain-text by default.
LDAPS
Carries LDAP directory queries over TLS.
Dev & ops
FTP
Transfers files between hosts. Plain-text with no encryption.
SSH
Provides an encrypted remote shell. Supports port forwarding and file transfer.
Telnet
Provides a remote shell over plain text. No encryption.
DNS
Resolves domain names to addresses. Runs over UDP and TCP.
DHCP
Assigns IP addresses to hosts over UDP. Servers listen on 67, clients on 68.
NTP
Synchronizes clocks across hosts over UDP.
SNMP
Collects metrics from network devices. Used for monitoring.
SNMP trap
Receives unsolicited SNMP traps and alerts from devices.
SMB
Shares files and printers on Windows networks. Carries modern SMB over TCP.
IKE
Negotiates IPsec security associations over UDP. Used for VPN setup.
Syslog
Receives log messages over UDP.
RTSP
Controls streaming media sessions. Used by IP cameras and media servers.
SOCKS
Proxies TCP connections through a SOCKS server.
NFS
Shares files across Unix and Linux networks.
Docker
Exposes the Docker daemon API. Port 2376 wraps it in TLS.
RDP
Provides remote desktop access to Windows hosts.
SIP
Sets up VoIP call sessions. Signaling for voice and video calls.
Vite
Serves the Vite dev server for frontend development.
Kibana
Serves the Kibana dashboards over HTTP.
VNC
Shares a remote desktop session. The default display port for VNC servers.
Kubernetes
Serves the Kubernetes API server over TLS.
Jupyter
Serves Jupyter notebooks over HTTP. Also a common alternate HTTP port.
Portainer
Serves the Portainer Docker management UI. Also the default PHP-FPM port.
Prometheus
Serves the Prometheus web UI and metrics endpoints.