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
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”
- Assign article topics to students. – provide online links.
- Have students read and complete handout.
- Students will continue to mix through the room and share and record the topic and key points in the “Jig Saw” section of the handout.
Groups Share.
Wrap-up: What is DNS? Questions
Lead a discussion reviewing the IP and DNS systems.
- Why does the Internet use IP addresses?
- Why don’t we need to know IP addresses?
- Why do we need a Domain Name System?
- Why don’t we all maintain our own DNS?
- Is there one big DNS for the entire Internet?
- How do you think all these DNS servers are maintained?
Prompts: Security
- What is one vulnerability of DNS and how is that vulnerability attacked?
- What are the implications of an attack on a DNS server (or severs) - how does this affect your life?
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.