Vol 1 Part 4: IPv4 Addressing

Question 1

How many bits are in an IPv6 address?

Answer 1

128 bits, 8 hextets. Each hextet is 16 bits, meaning they are essentially 2 octets.

Question 2

What is the private IP range for a class A network?

Answer 2

10.0.0.0-10.255.255.255

Question 3

What is the private IP range for a class B network?

Answer 3

172.16.0.0-172.31.255.255

Question 4

Private IP address space is determined by what guideline?

Answer 4

RFC 1918

Question 5

Class A, Class B, and Class C networks are all examples of what kind of network?

Answer 5

Unicast

Question 6

How can you derive the number of subnets using the CIDR?

Answer 6

Once you have found your interval between subnets (32, 64, 128 etc.) divide 256 by that interval. This gives you your total number of subnets.

Question 7

What is the range for public IP addresses by network class (classful)? Give the range for A, B, and C class networks.

Answer 7

A- 0.0.0.0-126.255.255.255
B- 128.0.0.0-191.255.255.255
C- 192.0.0.0-223.255.255.255

Question 8

A subset of public IP networks to each company instead of an entire public IP network is known as what?

Answer 8

Used Classless InterDomain Routing (CIDR)

Question 9

Why do we Subnet?

Answer 9

To divide hosts of similar needs into sub networks, enabling them to operate on a more efficient network .

Question 10

Where in the IP range is the Broadcast address?

Answer 10

The last IP address in the range

Question 11

How many bits are in an IPv4 address?

Answer 11

32 bits, 4 octets, 8 bits per octet.

Question 12

How many network bits does a Class A, Class B, and Class C have?

Answer 12

A- 8
B- 16
C- 24

Question 13

What is the private IP range for a class C network?

Answer 13

192.168.0.0-192.168.255.0

Question 14

What are the 3 class of networks?

Answer 14

A, B, C

Question 15

How can you derive the subnet ID with a subnet mask?

Answer 15

Take the last number in the subnet mask and subtract it from 256. This gives you the interval between subnets in that octet. From here, divide up that octet into intervals starting with .0 until you find the range of your subnet. The first address in the range is your subnet ID.

Ex. /18 CIDR = 11111111.11111111.11000000.00000000
That binary mask converts to 255.255.192.0
256-192=64. Our subnet ranges are .0-.63, .64-.127 etc.

Question 16

An IPv4 address consists of 32 bits. What are the two categories that these bits are divided into?

Answer 16

Network bits and Host Bits

Question 17

When looking at an IP range, the /x is the CIDR. What does the CIDR represent?

Answer 17

The number of network bits. This means if you see a /24, the first 24 bits are network bits.

Question 18

Where in the IP range is the Subnet ID?

Answer 18

The first IP address in the range

Question 19

What is Network Address Translation (NAT)?

Answer 19

Allows private networks to traverse public networks by assigning you a public IP address.

Question 20

When looking at a CIDR, how can you convert that value into a binary subnet mask?

Answer 20

The CIDR number represents the number of 1s in the binary mask starting from left to right ie. a CIDR of /8 would be a binary mask of 11111111.00000000.0.0

Question 21

How can you derive the number of hosts on the network using the CIDR?

Answer 21

Once you have found your subnet ID and your broadcast ID, take the last network octet and subtract it from the first network octet, then add one. Then, multiply this number by 256 for as many octets you have other than the last octet. This gives you total usable IPs, but subtract two to account for the subnet ID and broadcast IP to get the number of host IPs.