Week 6 - Digging into DNS*

Question 1

What are public DNS servers?

Answer 1

public DNS servers are free to be used by anyone

Question 2

What are Level 3’s public DNS server addresses?

Answer 2

4.2.2.1 - 4.2.2.6

Question 3

What are Google’s public DNS server addresses?

Answer 3

8.8.8.8 and 8.8.4.4.

Question 4

What do public DNS servers use to be available globally?

Answer 4

anycast

Question 5

Most DNS servers respond to _____ to test connectivity

Answer 5

ICMP echo requests, can use ping to test connections

Question 6

What’s a way your DNS requests could be hijacked?

Answer 6

outbound DNS requests redirect users to malicious sites using a fake DNS entry

Question 7

Who is responsible for assigning individual domain names to other orgs or individuals?

Answer 7

Registrar

Question 8

What type of system is DNS? (overall)

Answer 8

Global hierarchy with ICANN at the top level

Question 9

Can domain names be transferred? How?

Answer 9

Yes, you just configure your DNS settings to contain a special string of characters (from registrar) to confirm you own the domain and are transferring it

Question 10

Do domain names expire?

Answer 10

Yes, you have to keep on top of them or someone else could steal it

Question 11

What was the most notable organization that was responsible for almost all domains?

Answer 11

Network Solutions, Inc.

Question 12

How do you have access to a DNS as a consumer?

Answer 12

ISPs give you access to a recursive name server as part of the service

Question 13

What is a host file?

Answer 13

A host file is a file where each line contains an IP address and the host name it can be referred to as

Question 14

What took care of evaluating host files?

Answer 14

Networking stack

Question 15

In a host file, what would be considered the ‘domain’ name?

Answer 15

Host name

Question 16

What is a loopback address?

Answer 16

an address where you send traffic to yourself

Question 17

What’s the loopback address for IPv4?

Answer 17

127.0.0.1

Question 18

What’s the loopback address for IPv6?

Answer 18

::1 localhost

127.0.0.1 localhost::1 localhost

Question 19

On major OS, what is examined before a DNS resolution attempt occurs?
What can this force an individual computer to think?

Answer 19

Host file

It can make a computer think a certain domain name always points to a specific IP address (hackers!)

Question 20

What security concern is there for host files?

Answer 20

Host files are a popular way for viruses to disrupt/redirect user traffic

Question 21

For the internet layer, what command displays the current network configuration information?

Answer 21

ipconfig