U1Ch2L12b_DNS Security
Purpose: Students will see both the problems created and solved by DNS
Show Video Again:Replay “The Internet: IP Addresses & DNS” (Start at: 4:15 - 5:12)
https://www.youtube.com/watch?v=5o8CwafCxnU&feature=youtu.be&t=4m12s
Note: View Discussions Questions below prior to beginning this segment.
Activity #2- DNS Security (partners)
This system however was not designed to be secure and has resulted in some major security incidents over time.
- Handout: “Research: DNS in the Real World”
- Partners select an article topic. – Click Here For Online Links!
(First Come...First Serve!!)
- Partners read and 1. Summarize the Article, 2. State the Key Points and 3. State a fact that they found interesting.
- Partners will mix through the room and share and record the topic and key points in the “Jig Saw” section of the handout with the other students
Partners will share the fact they found interesting.
Wrap-up: What is DNS? Questions
- Why does the Internet use IP addresses?
- Why don’t we need to know IP addresses?
- Why do we need a Domain Name System?
- Is there one big DNS for the entire Internet?
- Why is DNS so vulnerable to attack?
Answers to the discussion questions:
- The Internet is basically a network of computers sending messages to request information and computers replying to messages to satisfy information requests. Computers need to identify “from” and “to” for all messages. Computer speak in numbers, not names.
- All communication online is via IP addresses. However, we are more familiar with human readable names, most notably URLs like “Code.org” or “Google.com.”
- We need a way to translate human-readable names into IP addresses.
- It is inefficient for everyone on the Internet to maintain a table of IP addresses.
- The DNS is NOT centralized, but it’s not completely autonomous and distributed like routing, either. There is a hierarchical system of servers to maintain an authoritative table that, like a phone book, others can consult when they need to find an address.
- A properly functioning DNS system requires collaborative efforts among all users to ensure it is up to date and accurate.