IP addresses and domain names in Intro to Computing - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding IP Address Classes

Which of the following IP addresses belongs to a Class B network?

A 224.0.0.1

B 10.0.0.1

C 192.168.1.1

D 172.16.0.1

💡 Hint

Recall that Class B IP addresses have their first octet between 128 and 191.

Class B IP addresses range from 128.0.0.0 to 191.255.255.255. The address 172.16.0.1 falls within this range.

❓ trace

intermediate

Domain Name Resolution Process

Consider the following simplified steps of resolving a domain name to an IP address. Which step happens third?

1. User types a domain name in the browser.
2. Browser checks local cache for IP address.
3. Request sent to recursive DNS server.
4. Recursive server queries root DNS server.

A Browser checks local cache for IP address.

B Request sent to recursive DNS server.

C User types a domain name in the browser.

D Recursive server queries root DNS server.

💡 Hint

Think about the order from user action to external queries.

First, the user types the domain name, then the browser checks its cache. If not found, it sends a request to the recursive DNS server, which is the third step.

❓ Comparison

advanced

Comparing IPv4 and IPv6 Addresses

Which statement correctly compares IPv4 and IPv6 addresses?

A IPv4 addresses are 128 bits long; IPv6 addresses are 32 bits long.

B IPv4 addresses use hexadecimal notation; IPv6 addresses use decimal notation.

C IPv4 addresses are written in four decimal numbers separated by dots; IPv6 addresses use eight groups of hexadecimal numbers separated by colons.

D IPv4 addresses support more unique addresses than IPv6.

💡 Hint

Recall the length and notation style of each IP version.

IPv4 addresses are 32 bits long and written as four decimal numbers separated by dots. IPv6 addresses are 128 bits long and written as eight groups of hexadecimal numbers separated by colons.

❓ identification

advanced

Identifying Valid Domain Names

Which of the following is a valid domain name according to standard rules?

A example.com

B -example.com

C example_site.com

D example..com

💡 Hint

Domain names cannot start with a hyphen or have consecutive dots.

Valid domain names can contain letters, numbers, and hyphens but cannot start or end with a hyphen, nor have consecutive dots. 'example.com' follows these rules.

🚀 Application

expert

Calculating Number of Hosts in a Subnet

You have an IPv4 subnet with the mask 255.255.255.240. How many usable host IP addresses are available in this subnet?

A 14

B 16

C 30

D 32

💡 Hint

Count the number of bits available for hosts and subtract network and broadcast addresses.

The subnet mask 255.255.255.240 corresponds to 28 bits for network and 4 bits for hosts. 2^4 = 16 addresses total. Subtract 2 for network and broadcast addresses, leaving 14 usable hosts.