Hands-on LabIT Fundamentals · Module 03

Lab: Module 03: Networking and the Internet

Lab 00: Networking Commands and HTTP Requests

Objective

Use networking commands to test connectivity, look up domain names, and make HTTP requests from the command line.

Prerequisites

  • A terminal application:
    • macOS: Terminal.app (pre-installed in Applications > Utilities)
    • Windows: Git Bash (bundled with Git for Windows)
    • Linux: Terminal (pre-installed)
  • Module 02 (The Command Line) for basic terminal skills

Duration

10 to 12 minutes

Instructions

Step 1: Test Network Connectivity with Ping (~3 min)

The ping command sends small packets to a server and measures the response time. The flag to limit the number of packets differs between operating systems.

macOS/Linux:

ping -c 3 google.com

Windows (Git Bash):

ping -n 3 google.com

Windows (PowerShell):

ping -n 3 google.com

Expected output (times and IP will vary):

PING google.com (142.250.80.46): 56 data bytes
64 bytes from 142.250.80.46: icmp_seq=0 ttl=117 time=12.3 ms
64 bytes from 142.250.80.46: icmp_seq=1 ttl=117 time=11.8 ms
64 bytes from 142.250.80.46: icmp_seq=2 ttl=117 time=12.1 ms

--- google.com ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max/stddev = 11.8/12.1/12.3/0.2 ms

If you see replies, your computer can reach Google's servers. The time value shows the round-trip latency in milliseconds.

Step 2: Look Up a Domain Name with nslookup (~3 min)

The nslookup command queries DNS to find the IP address associated with a domain name.

nslookup google.com

Expected output (addresses will vary):

Server:		192.168.1.1
Address:	192.168.1.1#53

Non-authoritative answer:
Name:	google.com
Address: 142.250.80.46

The Server line shows your DNS resolver (usually your router). The Address line under Non-authoritative answer shows the IP address that google.com resolves to.

Step 3: Make an HTTP Request with curl (~4 min)

The curl command sends HTTP requests from the command line. The -s flag runs it in silent mode (no progress bar).

curl -s https://httpbin.org/ip

Expected output (your IP will differ):

{
  "origin": "203.0.113.42"
}

This calls a public API that returns your public IP address in JSON format.

View HTTP response headers:

curl -s -I https://httpbin.org/ip

Expected output (values will vary):

HTTP/2 200
content-type: application/json
content-length: 32

The -I flag shows only the response headers. Notice the 200 status code (success) and the content-type: application/json header.

Validation

Confirm the following before moving on:

  • Running ping -c 3 google.com (or ping -n 3 google.com on Windows) returns replies with response times
  • Running nslookup google.com returns an IP address
  • Running curl -s https://httpbin.org/ip returns your public IP in JSON format

Cleanup

No files or directories were created during this lab. No cleanup is needed.

Challenge (Optional)

  1. Use nslookup to look up the IP address for aws.amazon.com. Compare the result to google.com. Are they in the same IP range?

  2. Use curl to make a request that returns a 404 status code:

    curl -s -o /dev/null -w "%{http_code}" https://httpbin.org/status/404

    Expected output: 404

  3. Try curl -s https://httpbin.org/headers to see what HTTP headers your terminal sends with each request.

AWS Bootcamp: From Novice to Architect Author: Samuel Ogunti License: CC BY-NC 4.0

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