6.4. IP Addresses and Domain Names

This lesson has students use a DNS simulator app to send messages to other clients on a router. They learn about DNS, IP addresses, and packets.

CSP Framework
Big Idea 4: Computing Systems and Networks (CSN)
Enduring Understanding CSN-1: Computer systems and networks facilitate how data are transferred.
Learning Objective CSN-1.C: Explain how data are sent through the Internet via packets.
Skill 5.A CSN-1.C.1 CSN-1.C.2 CSN-1.C.3 CSN-1.C.4 Essential Knowledge CSN-1.C.1: Information is passed through the Internet as a data stream. Data streams contain chunks of data, which are encapsulated in packets. Essential Knowledge CSN-1.C.2: Packets contain a chunk of data and metadata used for routing the packet between the origin and the destination on the Internet, as well as for data reassembly. Essential Knowledge CSN-1.C.3: Packets may arrive at the destination in order, out of order, or not at all. Essential Knowledge CSN-1.C-4: IP, TCP, and UDP are common protocols used on the Internet.

Professional Development

The Student Lesson: Complete the activities for Mobile CSP Unit 6: Lesson 6.4 IP Addresses and Domain Names.

Materials

• Computer lab with projection system
• Slides
• Tablets

6.4.1. Learning Activities

Estimated Length: 45 minutes

• Hook/Motivation (5 minutes):
• Experiences and Explorations (35 minutes):
  • Lecture Video (7:55) and slides describe the how the IP address system and the Domain Name System work together to identify data and network locations.
  • DNS Network Simulation Activities allow students to explore how the DNS provides look-up services to translate hostnames (login IDs) to IP addresses and how IP addresses can be used to communicate between hostnames.
    The teacher needs to run the DNS simulator app first and push the NEW CLASS CODE button and write this class code on the board so that all the students can enter that class code in their apps. This will ensure that they can see each other on the simulated network.
    
  • POGIL Activity allows students to explore how to enhance the widget to handle multiple messages.
    Solution:

    Recipient	Sender#
    mailbox ← empty list Repeat every 3 seconds { Repeat until mailbox is empty list { Remove_msg_at_front_of_list } }	recipient's mailbox ← Insert_at_end_of_list("sender#: ip address : message ")

    
    Students could also use Insert_at_end and Remove_at_end This strategy is a First In First Out (FIFO) approach which turns the list into a data structure called a queue in comparison to a Last In First Out (LIFO) approach for a stack. Students do not need to know these data structures, but you can talk about whether a FIFO and LIFO approach is necessary for the queueing of messages. Some examples of FIFO in real life are waiting in lines at the bank, cashier, kiosk, bus, etc., as well as sending a document to the printer where it waits in a FIFO printer queue to be processed.
• Rethink, Reflect and/or Revise (5 minutes): Review how the Internet works, including the important terms covered in the videos. Students should complete a reflection on their portfolio based on the activities (this may be assigned for homework), and complete the interactive exercises.

AP Classroom

The College Board's AP Classroom provides a question bank and Topic Questions. You may create a formative assessment quiz in AP Classroom, assign the quiz (a set of questions), and then review the results in class to identify and address any student misunderstandings.The following are suggested topic questions that you could assign once students have completed this lesson.

Suggested Topic Questions:

Assessment Opportunities and Solutions

Solutions Note: Solutions are only available to verified educators who have joined the Teaching Mobile CSP Google group/forum in Unit 1.

• Quizly Solutions
• Portfolio Reflection Questions Solutions

Assessment Opportunities

You can examine students’ work on the interactive exercise and their reflection portfolio entries to assess their progress on the following learning objectives. If students are able to do what is listed there, they are ready to move on to the next lesson.

• Interactive Exercises:
• DNS Network Simulation
• Modification of Protocol to Handle Multiple Messages
• Modification of Protocol to Break Messages into Multiple Packets
• Portfolio Reflections:
  • LO 5.2.1 - Students should be able to explain how programs implement algorithms. Students are given practice on this skill with the POGIL exercises.
  • LO 6.1.1 - Students should be able to explain the abstractions in the Internet and how the Internet functions. Use of the DNS simulator allows students to learn how DNS works on the Internet.
  • LO 6.2.1 - Students should be able to explain the characteristics of the Internet and the systems build on it. The DNS is a key component in the infrastructure of the Internet.
  • LO 6.2.2 - Students should be able to explain how the characteristics of the Internet influence the systems built on it. Routing and address are key components to a distributed system such as the Internet.
• In the DNS Simulation, look for: students ablity to ask the DNS for the IP addresses of other login IDs on the system. Also look for message exchanges between the student and the Amazon BOT as well as between students and their peers.

Differentiation: More Practice

If students are struggling with lesson concepts, have them review the following resources:

• Internet FAQ — the Internet Society's page provides concise answers to frequently asked questions about the Internet, including what it is and how it works.

Background Knowledge

• Internet FAQ — the Internet Society's page provides concise answers to frequently asked questions about the Internet, including what it is and how it works.
• Whitepaper — a fairly concise but authoritative explanation of Internet infrastructure.
• Wikipedia — an authoritative and comprehensive resource with around 90 references to original sources.

6.4.2. Professional Development Reflection

Discuss the following questions with other teachers in your professional development program.

I am confident I can teach this lesson to my students.
• 1. Strongly Agree
• 2. Agree
• 3. Neutral
• 4. Disagree
• 5. Strongly Disagree