Name Service Method Quiz Explanation

The correct answers are indicated below, along with text that explains the correct answers.
 
1. What is the simplest name service method?
Please select the best answer.
  A. A list of IP addresses and host names saved in a text file
  B. The Internet-wide Domain Name Service
  C. A list of aliases only, saved in a text file
  D. A list of DNS server addresses
  The correct answer is A.
The simplest name service method is a list of IP addresses and host names saved in a text file. This method is available before any networking configuration has been completed.

2. On UNIX systems, how is the /etc/hosts file configured?
Please select the best answer.
  A. It lists aliases in one column and IP addresses in the other.
  B. It lists IP addresses in one column and host names in another.
  C. It lists DNS server names in one column and host names in another.
  D. It lists aliases in one column and host names in another.
  The correct answer is B.
On UNIX systems, the /etc/hosts file is configured by listing IP addresses in one column and host names in the other.

3. To create a DNS client, what must you know?
Please select the best answer.
  A. The host name of at least one DNS name server and your own DNS domain name
  B. The IP address of at least one DNS name server and your own host name
  C. The IP address of at least one DNS name server and your own DNS domain name
  D. The host name of at least one DNS server and your own numeric IP address
  The correct answer is C.
To create a DNS client, you must know the IP address of at least one DNS name server and your own DNS domain name. You must supply one nameserver line, but you may supply up to three.