Network+ - IPv4 Addressing

Which of the following is a broadcast to all IPv4 network IDs? A. 255.255.255.255 B. 192.168.255.255 C. 10.255.255.255 D. 127.0.0.1

A. 255.255.255.255 Explanation: An IP address with all ones is a broadcast to all networks. All binary ones in an IPv4 address translates to a decimal notation of 255.255.255.255

An IPv4 address is comprised of how many binary octets? A. 4 B. 8 C. 12 D. 32

A. 4 Explanation: A binary octet includes 8 bits and an IPv4 address includes 4 octets.

CIDR (Classless Inter-Domain Routing) is a term that is similar to VLSM (Variable Length Subnet Masking). A. True B. False

A. True Explanation: VLSM and CIDR are related terms meaning subnets can be created by extending the mask bits out to any necessary position. This was made possible by removing the mask restriction of the original default class-based system.

Which of the following IP addresses is a Class A address in the IPv4 Classful system? A. 128.95.66.3 B. 10.45.6.2 C. 255.255.255.254 D. 192.168.100.1

B. 10.45.6.2 Explanation: Class A default addresses have a first octet with the range of 1 - 126

A single octet in an IPv4 address can be represented as a decimal number between 0 and _______. A. 254 B. 255 C. 256 D. 512

B. 255 Explanation: A binary octet includes 8 bits. When all 8 bits are ones it equals 255 in decimal notation. 128+64+32+16+8+4+2+1 = 255. Technically speaking there are 256 total possibilities including an octet of all zeros, but the highest possible decimal representation is still 255.

The CIDR notation of /16 can also be represent as what subnet mask in decimal notation? A. 255.0.0.0 B. 255.255.0.0 C. 255.255.255.0 D. 255.255.224.0

B. 255.255.0.0 Explanation: A CIDR of /16 is 16 ones in the mask. So, a /16 indicates a subnet mask with the first two octets filled with ones. If the complete first two octets are filled with ones that gives a subnet mask of 255.255.0.0

A single octet in an IPv4 address includes how many binary digits? A. 4 B. 8 C. 12 D. 32

B. 8 Explanation: An octet includes 8 binary digits (aka bits). What gives this away is the fact that it is called an octet as "oct" means 8. Just like the name octopus describes its 8 arms.

Given the following IP address in CIDR notation, what is the network/subnet ID? 192.168.100.50/24 A. 192.168.0.0 B. 192.168.100.50 C. 192.168.100.0 D. 192.0.0.0

C. 192.168.100.0 Explanation: A CIDR notation of /24 represents a network with the complete first 3 octets as the network ID and the complete last octet as host bits.

An IPv4 address is made up of how many total binary digits? A. 128 B. 64 C. 32 D. 16

C. 32 Explanation: An IPv4 address includes 4 octets each with 8 bits totaling to 32 bits.

The IP address 192.168.0.1 is part of which IPv4 default class? A. Class A B. Class B C. Class C D. Class D

C. Class C Explanation: Class C default addresses have a first octet with the range of 192 - 223.

The subnet mask 255.255.255.0 can also be represented in CIDR notation as __________. A. /32 B. /26 C. /16 D. /24

D. /24 Explanation: CIDR notation is a representation of the number bits that are turned on (aka the number of ones) in the subnet mask. A subnet mask of 255.255.255.0 has the first three octets with all ones. The CIDR notation can be calculated by adding up the number of ones in the maks. 8+8+8+0=24 which gives a CIDR notation of /24.

Which of the following is an IPv4 loopback address? A. 224.0.0.1 B. 192.168.0.1 C. 1.1.1.1 D. 127.0.0.1

D. 127.0.0.1 Explanation: The entire range of 127.0.0.0/8 is reserved for loopback in IPv4. So, anything that begins with 127 is a loopback address.

Given the following IP address and subnet mask, what is the network/subnet ID? 192.168.49.52 255.255.255.0 A. 192.0.49.0 B. 192.168.0.52 C. 192.168.49.52 D. 192.168.49.0

D. 192.168.49.0 Explanation: a subnet mask of 255.255.255.0 represents a network with the complete first 3 octets as the network ID and the complete last octet as host bits.