Key Networking Protocols for DevOps

HTTP and HTTPS

• Ports: 80 (HTTP), 443 (HTTPS)

• What they do: HTTP is used to send web pages and stuff over the internet. HTTPS is just like HTTP, but safer because it uses encryption.

• Example: If you want people to see your website, you make sure it loads over HTTPS so their info is protected when they visit129.

SSH (Secure Shell)

• Port: 22

• What it does: SSH lets you connect safely to another computer, usually a server, so you can run commands or move files.

• Example: You use SSH to log into a remote server and maybe restart a service or check logs139.

FTP and SFTP

• Ports: 21 (FTP), 22 (SFTP uses SSH)

• What they do: FTP is for moving files between computers, but it’s not secure. SFTP is the safer version because it uses SSH.

• Example: You might use SFTP to upload a backup file from your laptop to a server9.

DNS (Domain Name System)

• Port: 53

• What it does: DNS turns website names (like google.com) into IP addresses that computers use to find each other.

• Example: When you set up a new website, you update DNS so people can reach it by typing the name instead of a bunch of numbers19.

SMTP, IMAP, and POP3

• Ports: 25 (SMTP), 143 (IMAP), 110 (POP3)

• What they do: These are all about email. SMTP sends emails out, IMAP lets you read emails from the server, and POP3 downloads them to your computer.

• Example: You might set up SMTP so your app can send out password reset emails to users9.

SNMP (Simple Network Management Protocol)

• Port: 161

• What it does: SNMP helps you check on devices like servers and routers, so you know if they’re working right.

• Example: You can use SNMP to see how much memory a server is using19.

RDP (Remote Desktop Protocol)

• Port: 3389

• What it does: RDP lets you connect to a Windows computer and see its desktop, even if you’re far away.

• Example: If your Windows server has a problem, you can use RDP to log in and fix it without being in the same room9.

Kubernetes and Docker Ports

• Ports: 2379–2380 (etcd), 6443 (Kubernetes API), 10250 (Kubelet), 2375 (Docker)

• What they do: These ports are used by tools like Kubernetes and Docker so containers and clusters can talk to each other.

• Example: When you set up a Kubernetes cluster, you need to make sure these ports are open so everything works together19.