🛠️ Essential Networking Commands Cheat Sheet for DevOps

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If you're trying to debug why your server isn't responding, or why a DNS record isn't resolving, or if your app just randomly hangs — these are the commands you’ll turn to.

So here it is — a quick but powerful guide to the most used networking commands every DevOps learner (or practitioner) should know.

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1. 🧠 ping – Check If a Host Is Reachable

ping.google.com

What it does:
Sends ICMP echo requests to a target host to check if it’s alive and how long it takes to respond.

When to use:

• Check internet connection

• Test server uptime or response

• Quick network diagnosis

🔹 Sample Output:

64 bytes from 142.250.183.14: icmp_seq=1 ttl=115 time=25.3 ms

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2. 🗺️ traceroute (Linux/macOS) / tracert (Windows) – Trace the Route to a Host

traceroute github.com #Linux/macOS

tracert github.com #Windows

What it does:
Shows the route (hops) your request takes through the internet to reach the destination.

When to use:

• Find where a connection is slowing down or breaking

• See how many hops are between your machine and the server

🔹 Useful when ping works, but your app is still slow or stuck.

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3. 🌐 curl – Make HTTP Requests from Terminal

curl -I https://example.com #Get only headers

curl -X GET https://api.site.com/data

What it does:
Interacts with web servers, APIs, and endpoints directly from the command line.

When to use:

• Test API endpoints

• Check HTTP headers or response codes

• Simulate GET/POST requests

🔹 Try this to check if a website is up:

curl -Is https://yourdomain.com | head -n 1

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4. 🛰️ netstat – Show Network Connections and Listening Ports

netstat -tuln

What it does:
Displays current network connections, listening ports, and routing tables.

When to use:

• Check which ports are open and which service is using them

• Debug port conflicts

• See if your app/server is listening

🔹 Common flags:

• -t → TCP

• -u → UDP

• -l → Listening

• -n → Show numbers (no DNS resolution)

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5. 🔍 dig – DNS Lookup (Linux/macOS)

dig google.com

What it does:
Performs detailed DNS queries and shows how domain names are resolved.

When to use:

• Check DNS propagation

• Validate custom DNS records (A, CNAME, TXT, etc.)

• Diagnose DNS-related errors

🔹 To check just the A record:

dig +short google.com

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6. 🕵️‍♂️ nslookup – DNS Lookup (Cross-Platform Alternative)

nslookup github.com

What it does:
Resolves domain names to IP addresses — works on Linux, macOS, and Windows.

When to use:

• Quick domain-to-IP checks

• Cross-check DNS if dig isn’t available

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Bonus: Combining Commands

ping -c 3 google.com && curl -I https://google.com

Test both connectivity and web response in one go.

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✅ Quick Reference Summary Table

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🧠 What I Learned

Honestly, using these commands helped me understand networking more than any theory ever did. Once you practice a few real-life debugging cases — slow websites, DNS misconfigurations, SSL issues — these tools become second nature.

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🏁 Final Tip

Always start with:

ping → dig → netstat

This flow helps you identify:

• Is the server up?

• Is the service running?

• Is DNS working?

• Is the port open?