What is the default port for SSH?

SSH uses port 22 by default. Many security-conscious teams change this to a non-standard port (e.g., 2222) to reduce automated attack attempts, though this is security through obscurity rather than true security. Always combine with key-based auth and fail2ban regardless of port.

What ports do I need to open for a web application?

Minimum: port 80 (HTTP) for redirect and port 443 (HTTPS) for traffic. For direct database access: 5432 (PostgreSQL) or 3306 (MySQL). For Redis: 6379. For the application server, a common pattern is to only expose 80/443 publicly and keep all other ports behind a VPN or private subnet.

What ports does Kubernetes use?

Kubernetes uses port 6443 for the API server (HTTPS), 10250 for kubelet, 10251 for kube-scheduler, 10252 for kube-controller-manager, and 2379-2380 for etcd. Node ports for services range from 30000-32767 by default. Always restrict API server access to trusted IP ranges.

Why does Redis use port 6379?

Redis creator Salvatore Sanfilippo chose 6379 because it spells MERZ on a phone keypad — the name of an Italian TV personality. There is no technical reason. It is simply a convention that stuck. Always bind Redis to localhost or a private network interface and never expose it publicly.

What is the difference between TCP and UDP ports?

TCP (Transmission Control Protocol) provides reliable, ordered delivery with acknowledgment — used for HTTP, SSH, databases. UDP (User Datagram Protocol) is faster but unreliable, no guaranteed delivery — used for DNS, DHCP, video streaming, VoIP. Some services like DNS use both TCP and UDP on the same port.

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Common Network Ports Reference

Searchable reference of 40+ common network ports — SSH, HTTP, HTTPS, MySQL, Redis, Kafka, Kubernetes and more. Protocol, service name, and description. Free developer reference.

40 ports

20TCPFTP DataFile Transfer Protocol — data transfer

21TCPFTP ControlFile Transfer Protocol — command control

22TCPSSHSecure Shell — encrypted remote login

23TCPTelnetUnencrypted remote login (deprecated)

25TCPSMTPSimple Mail Transfer Protocol — email sending

53TCP/UDPDNSDomain Name System — hostname resolution

67UDPDHCP ServerDynamic Host Configuration Protocol

68UDPDHCP ClientDHCP client port

80TCPHTTPHyperText Transfer Protocol — web traffic

110TCPPOP3Post Office Protocol — email retrieval

143TCPIMAPInternet Message Access Protocol — email

443TCPHTTPSHTTP Secure — encrypted web traffic

465TCPSMTPSSMTP over SSL — secure email sending

587TCPSMTP (TLS)SMTP with STARTTLS — modern email submission

993TCPIMAPSIMAP over SSL — secure email retrieval

995TCPPOP3SPOP3 over SSL — secure email retrieval

1433TCPMSSQLMicrosoft SQL Server database

1521TCPOracle DBOracle database default port

2181TCPZookeeperApache ZooKeeper coordination service

2375TCPDockerDocker daemon — unencrypted

2376TCPDocker TLSDocker daemon — TLS encrypted

3000TCPDev ServerCommon dev server port (React, Node.js)

3306TCPMySQLMySQL database server

4200TCPAngularAngular CLI development server

5000TCPFlaskPython Flask development server

5432TCPPostgreSQLPostgreSQL database server

5672TCPRabbitMQRabbitMQ AMQP message broker

6379TCPRedisRedis in-memory data store

6443TCPKubernetes APIKubernetes API server

8080TCPHTTP AltAlternate HTTP — Tomcat, proxies

8443TCPHTTPS AltAlternate HTTPS port

8888TCPJupyterJupyter Notebook server

9000TCPSonarQubeSonarQube code quality server

9090TCPPrometheusPrometheus monitoring server

9092TCPKafkaApache Kafka message broker

9200TCPElasticsearchElasticsearch REST API

9300TCPES TransportElasticsearch node transport

10250TCPKubeletKubernetes kubelet API

15672TCPRabbitMQ UIRabbitMQ management interface

27017TCPMongoDBMongoDB database server

About This Tool

A searchable reference of the most commonly used network port numbers for developers, DevOps engineers, and system administrators. Covers well-known ports (0-1023) and common registered ports — SSH, HTTP, HTTPS, FTP, DNS, SMTP, MySQL, PostgreSQL, MongoDB, Redis, Kafka, Elasticsearch, Kubernetes, Docker, RabbitMQ, and many more. Filter by port number, service name, or description.