Common Protocols

Understanding Common Networking Ports and Their Use Cases

In the world of networking and IT infrastructure, understanding commonly used ports and their associated protocols is crucial. Each port serves as a gateway for specific services, enabling secure communication, application hosting, file transfers, and more.

Here’s a detailed guide to some of the most commonly used ports, their purposes, and example tools.

1. SSH (Secure Shell)

• Port: 22
• Purpose: Enables secure remote login and command execution on Linux servers.
• Use Case: Admin access to servers, deploying code, and configuration management.
• Example Tool: ssh, scp, rsync

2. HTTP (Hypertext Transfer Protocol)

• Port: 80
• Purpose: Serves unencrypted web traffic.
• Use Case: Web applications, load balancing, reverse proxy setup.
• Example Tool: nginx, apache2.

3. HTTPS (Hypertext Transfer Protocol Secure)

• Port: 443
• Purpose: Provides encrypted web traffic for secure communications.
• Use Case: Hosting secure web applications, SSL/TLS termination.
• Example Tool: nginx, apache2, letsencrypt.

4. FTP (File Transfer Protocol)

• Port: 21
• Purpose: Transfers files between servers.
• Use Case: File transfer (though often replaced by SFTP for added security).
• Example Tool: vsftpd, proftpd.

5. SFTP (SSH File Transfer Protocol)

• Port: 22 (Shared with SSH)
• Purpose: Securely transfers files using SSH.
• Use Case: Secure file uploads/downloads to remote systems.

6. DNS (Domain Name System)

• Port: 53
• Purpose: Resolves domain names to IP addresses.
• Use Case: Networking, troubleshooting, and service discovery.
• Example Tool: bind9, dnsmasq, systemd-resolved.

7. MySQL / MariaDB

• Port: 3306
• Purpose: Default port for MySQL and MariaDB databases.
• Use Case: Database management and application backends.
• Example Tool: mysql, mariadb.

8. PostgreSQL

• Port: 5432
• Purpose: Default port for PostgreSQL databases.
• Use Case: Application backends and data storage.
• Example Tool: postgresql.

9. Redis

• Port: 6379
• Purpose: Default port for the Redis in-memory data store.
• Use Case: Caching, message brokering, and session management.
• Example Tool: redis-server.

10. MongoDB

• Port: 27017
• Purpose: Default port for the MongoDB NoSQL database.
• Use Case: NoSQL data storage.
• Example Tool: mongod.

11. Jenkins

• Port: 8080
• Purpose: Default port for the Jenkins CI/CD server.
• Use Case: Continuous integration and deployment pipelines.
• Example Tool: jenkins.

12. Docker

• Port: 2375 (unencrypted), 2376 (encrypted)
• Purpose: Default port for the Docker daemon’s REST API.
• Use Case: Docker container orchestration and remote management.
• Example Tool: docker, docker-compose.

13. Kubernetes API Server

• Port: 6443
• Purpose: Default port for the Kubernetes API server.
• Use Case: Kubernetes cluster management and service discovery.
• Example Tool: kubectl, helm.

14. ElasticSearch

• Port: 9200 (HTTP), 9300 (Internal communication)
• Purpose: Default port for Elasticsearch REST API and cluster communication.
• Use Case: Full-text search and log aggregation.
• Example Tool: elasticsearch.

15. RabbitMQ

• Port: 5672
• Purpose: Default port for AMQP (Advanced Message Queuing Protocol).
• Use Case: Messaging queues and event-driven architectures.
• Example Tool: rabbitmq.

Conclusion

Networking ports play a vital role in enabling communication across systems and applications. Whether you are an administrator managing servers, a developer deploying web applications, or an architect designing infrastructure, understanding these ports and their use cases is essential for seamless operations and security.

Have a favorite tool or use case for any of these ports? Share your thoughts in the comments!