Module · DevOps Engineer

Networking

IPs, ports, DNS and the paths packets actually take.

5 topics6 interactive tasks

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TOPIC 01

IP Addressing & Routes

Which address is yours and where packets leave the machine.

What you'll practice

Trace Your Network Setup — guided · beginner

A command you'll meet

ip a

Open any task below to get the full step-by-step walkthrough — every command is explained, and the lab validator checks what you actually built.

Hands-On Tasks in This Topic (1)

beginner

Guided Task

Trace Your Network Setup

Every container and server has an IP, a route to the outside world and a way to test reachability. Find this machine's addresses and prove connectivity to the default gateway.

Environment: ubuntu:24.04Launch Lab ⚡

TOPIC 02

Ports & Sockets

How a single machine serves many services at once.

What you'll practice

Find What's Listening on Which Port — practice · beginner

A command you'll meet

ss -tlnp

Open any task below to get the full step-by-step walkthrough — every command is explained, and the lab validator checks what you actually built.

Hands-On Tasks in This Topic (1)

beginner

Practice Task

Find What's Listening on Which Port

'Port 8080 is in use' is a daily incident. Use ss to list listening sockets, find the port the app process listens on and record it.

Environment: ubuntu:24.04Launch Lab ⚡

TOPIC 03

DNS

Names to addresses — the directory service of the internet.

What you'll practice

Resolve a Hostname — guided · beginner

A command you'll meet

cat /etc/resolv.conf

Open any task below to get the full step-by-step walkthrough — every command is explained, and the lab validator checks what you actually built.

Hands-On Tasks in This Topic (1)

beginner

Guided Task

Resolve a Hostname

Before a connection is made, a name becomes an IP. Resolve lab.internal with dig, compare with /etc/hosts and record the answer.

Environment: ubuntu:24.04Launch Lab ⚡

TOPIC 04

HTTP & curl

The protocol every platform ultimately serves.

What you'll practice

Prove a Service Answers HTTP 200 — challenge · intermediate

A command you'll meet

docker run -d -p 8080:80 app:latest

Open any task below to get the full step-by-step walkthrough — every command is explained, and the lab validator checks what you actually built.

Hands-On Tasks in This Topic (1)

intermediate

Challenge

Prove a Service Answers HTTP 200

Deploy the app image on port 8080 and then prove — with curl, not faith — that it answers HTTP 200. This combines Docker and networking; the validator makes a real request against the port.

Environment: ubuntu:24.04 + dockerLaunch Lab ⚡

TOPIC 05

Reverse Proxies & Load Balancing

Put a proxy in front of your services so traffic is balanced and failures are noticed.

What you'll practice

Configure a Reverse Proxy — practice · intermediate
Add a Health Check to the Proxy — challenge · advanced

A command you'll meet

curl http://localhost:8080/health

A proxy is only as good as the health check behind it. Open the task below for the full walkthrough.

Hands-On Tasks in This Topic (2)

intermediate

Practice Task

Configure a Reverse Proxy

A reverse proxy terminates client connections and forwards them to your upstreams. Write an nginx configuration with an upstream block, a failure threshold and a proxy_pass rule.

Environment: ubuntu:24.04Launch Lab ⚡

advanced

Challenge

Add a Health Check to the Proxy

A proxy is only as good as its health check. Start the application, prove it answers, and script the exact same question so the proxy can keep asking it.

Environment: ubuntu:24.04 + dockerLaunch Lab ⚡