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DevOps Roadmap — Part 4: Linux Networking for DevOps

DevOps engineers do not just write pipelines. They make sure systems are reachable, secure, and stable.

If you do not understand networking, you will never understand cloud, Docker, or Kubernetes.

What Is Networking (In Simple Words)

Networking is how computers talk to each other.

• Your laptop talking to Google
• Your server talking to database
• Your app talking to users

DevOps is responsible when this communication fails.

IP Address — Identity of a Machine

Every machine has an IP address. It is like a phone number.

ip a

Common IP types:

• Private IP → internal network
• Public IP → internet access

Ping — Basic Connectivity Test

ping google.com

If ping fails:

• No internet
• DNS issue
• Firewall blocking

Ping is the first DevOps debugging tool.

Ports — Doors of a Server

Servers expose services using ports.

• 22 → SSH
• 80 → HTTP
• 443 → HTTPS
• 3306 → MySQL

ss -tuln

Open ports = attack surface. DevOps must keep them minimal.

DNS — Name to IP Translator

Humans remember names. Machines understand IPs.

nslookup google.com

If DNS fails:

• Website not reachable
• APIs break
• Cloud services fail

Firewall — Security Gatekeeper

Firewalls decide:

• Which ports are allowed
• Which traffic is blocked

sudo ufw status

sudo ufw allow 22

One wrong firewall rule can kill production.

Why Networking Is Critical for DevOps

CI/CD, cloud load balancers, containers, and microservices all depend on networking.

Most real-world outages are network-related, not code-related.

What You Should Practice

• Ping from server to internet
• Check ports before deploying app
• Understand private vs public IP
• Never expose unnecessary ports

Next Step in Roadmap

Now that you understand networking, we automate Linux using shell scripting — the backbone of DevOps automation.