Basic Networking Commands

Separate local configuration, name resolution, and remote connectivity checks.

Test connectivity, fetch web pages, inspect addresses, and understand DNS basics.

Outcome: Network commands feel like diagnostics, not hacking tools.

Mental model

Understand what is happening

Network commands may contact external servers.

Save downloads inside ~/linux-practice/downloads.

Some tools may not be installed by default; skip optional installs.

Guided lab

Work through the mission

Connectivity checks

Read-only

Sends ICMP probes to a public address and the local loopback interface. A reply is useful evidence; no reply is inconclusive because networks and hosts may block ICMP.

Terminal

ping -c 2 8.8.8.8
ping -c 1 localhost

Check DNS separately from connectivity

Read-only

Separates name lookup from ICMP reachability. If the IP address replies but name lookup fails, DNS is the likely layer to investigate. A failed ping alone does not prove the network is offline.

Terminal

getent hosts example.com
ping -c 1 example.com
ping -c 1 1.1.1.1

Fetch a web page

Safe

Downloads into the sandbox downloads folder. -L follows redirects; -I fetches headers only.

Terminal

mkdir -p ~/linux-practice/downloads
cd ~/linux-practice/downloads
curl -IL https://example.com
curl -L -o example.html https://example.com
head -5 example.html

Inspect network info

Read-only

Views addresses, routes, and listening ports.

Terminal

ip addr show | head -30
ip route show
ss -tuln | head -20
hostname -I

Checkpoint

Verify the mission

The checks identify which connectivity layer works.

Try it yourself

One step without a recipe

Download example.com into downloads and inspect the first lines.

Need a hint?

When a command fails with 'command not found,' don't immediately install it. Run `which command-name` or `type command-name` first. You might already have it under a different name, or it might be a shell builtin.

Explain it back

Before you move on

What does ping -c 2 mean?
Where should downloaded files go in this course?