Practice Use drills for recall and labs for real operating judgment.

LAB-NET-01 - Interfaces and IP Addresses

Identify local network interfaces and addresses so you can tell which interface is active and which address actually matters for the current network path.

NET Networking and Communication

Interfaces and IP Addresses

Identify local network interfaces and addresses so you can tell which interface is active and which address actually matters for the current network path.

20 min BEGINNER LINUX Field-verified
Prerequisites
Lab LAB-FS-01 - The Linux File System Tree
Success criteria
  • Identify the main local interface and its IP address.
  • Explain what loopback is for.
Safety notes
  • Do not bring interfaces down on a system you are actively using remotely.

Part A: The Field Guide

Before troubleshooting connectivity, you need to know which interface and address the system is actually using.

This lab keeps the goal simple:

  • inspect interfaces
  • identify your current address
  • separate loopback from the real network path

Important Distinction

The loopback address proves the local networking stack is alive. It does not prove that your machine can reach the wider network.

Part B: The Drill Deck

Terminal required: inspection first, no risky changes.

G
Guided Step by step - type exactly this and compare the result
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Exercise G1: Show the interface list

  1. Run ip -br a
  2. Identify the lo interface
  3. Identify the main non-loopback interface if present
  4. Note its IPv4 address if one is shown

Exercise G2: Look at the fuller view

  1. Run ip addr
  2. Find the inet line for your main interface
  3. Find the link/ether line
  4. Explain which one is the network address and which one is the hardware address

Exercise G3: Compare loopback and external identity

  1. Note the address on lo
  2. Note the address on your active network interface
  3. Explain why these serve different roles
S
Solo Task described, hints available - figure it out
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Exercise S1: Short explanation

In your own words, explain:

  1. what loopback is for
  2. why one machine may have more than one interface
  3. why the visible IP can differ by interface
  1. Run ip -br link
  2. Compare it with ip -br a
  3. Explain what disappears when you ask for the link layer instead of the address layer
M
Mission Real scenario - no hints, combine multiple skills
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Mission M1: Identify the interface that matters

Using only inspection commands, answer:

  1. which interface appears to be carrying normal network traffic
  2. which address is only for internal loopback use
  3. which details you would quote first if someone asked for your current local IP

If you can answer that cleanly, the first step of networking is under control.