Overview

Students conclude their study of the layers of the Internet by learning about two top-level protocols, HTTP and DNS. The lesson begins with a review of the layers students have already learned, namely the physical Internet, IP, and TCP / UDP. The lesson then dives into the core of the unit which is "What happens when I type an address into my browser?" Students will complete a brief activity to explore how the DNS works. Students then watch videos explaining how both DNS and HTTP work, taking notes and using a provided activity guide. The lesson concludes with a review of how the different layers of the Internet work.

Goals

Students will be able to:

Purpose

This lesson is designed to wrap up the series on how the Internet works and highlight the main design philosophies of openness, reliability, and scalability. However, actions taken by governments and organizations challenge some of these design philosophies and may hinder the ability of the World Wide Web to be truly worldwide. Students will begin thinking about some of the dilemmas caused by these conflicts, which they will explore further after this lesson.

Resources

Warm Up

Distribute: As students enter class, hand each of them a single IP address. You cut these out ahead of time from IP Address Labels - Teacher Resource. You could also use handwritten notes or any other medium that's convenient for you and your students.

Teaching Tip

Showing the Need for DNS: This quick unplugged activity helps students understand why the DNS exists in the first place. With devices joining the internet all the time it's impossible for each device to keep track of each other device's IP address.

Keep it Short: This activity can be done very quickly, typically in about 3 minutes, before students start to see the core challenge. If students start running away from you that's a good sign they've seen what makes this activity tricky!


Do This: Your goal is to create a list in your journals of every one of your classmates IP addresses. The only rules:

Circulate: As students are working, circulate quietly through the room.

Prompt: Discuss with your classmates the following prompts:

Discuss: Discuss responses to these questions with students, using the discussion goal to guide the conversation.

Discussion Goal: Main takeaways should include:


Remarks

Activity

Video #1: DNS

Prompt: As we watch the following video take notes on:

Display: Show The Internet: IP Addresses and DNS - Video on DNS, which explains how it works. Video will automatically start playing at the introduction of DNS.

Prompt: Discuss the following prompts with a partner:

Discuss: Have students discuss responses with their partners, then share out with the class. Focus on the main takeaways in the discussion goal.

Goal: The main takeaways from this video should be:


Video #2: HTTP and the World Wide Web

Remarks

Do This: As we watch this video take notes on the HTTP protocol.

Display: Watch The Internet: HTTP and HTML - Video

Prompt: Review these questions with a partner about HTTP

Discuss: Have students share out their responses with the class to make sure students understand the key takeaways about HTTP.

Discussion Goal: Here are the most important points for students to take away about HTTP and the way it works


Wrap Up

Journal: Review the key takeaways of the lesson and have students add new vocabulary to their journals: scalability, DNS, World Wide Web, HTTP

Distribute: Give students a copy of the Layers of the Internet - Activity Guide

Prompt: Using your Layers of the Internet activity guide to help you, explain how each of the different layers is involved when you go to a link like example.com?

Discuss: Use this final prompt as a review of everything covered in both today's lesson and those that came before. You'll actually probably want to start with the bottom of your review guide.

Discussion Goal: Use this final discussion to review not just this lesson but every protocol / layer of the Internet students have learned so far. You'd aim to see responses like the following:


Remarks

Assessment: Check for Understanding

Question: Choose the two statements that best describe the relationship between HTTP and the World Wide Web:

Question: In your own words explain the following about the Domain Name System:

Standards Alignment