IPVAAddress Basics

Question 1

What is an IP Address?

Answer 1

All devices (computer, phone, etc connecting to a network needs some kind of unique ID to be able to send and receive information. This unique
ID is the IP address! The IP address can be compared to your house address, which is used to send and receive mail and packages.

Question 2

IPv4 Address Anatomy

Answer 2

IPv4 addresses are made up of four sections. Each section is called an “octet”.
“Octet” means “group of eight things”. Each section (octet), in binary, is comprised of eight bits. IPv4 addresses have a total length of 32 bits.
The above IP address written out in binary is:

Question 3

Intro to Binary! (Let’s talk about human numbers first though!)

Answer 3

Binary is a lot more like our normal numbering system than you might think. Us humans normally use the “decimal” numbering system to count. That is–we use the numbers 0 through 9 for everything. Take the (decimal) number 4253 for instance. In elementary school, you may have learned something like this:

Instead of decimal (0 through 9), computers use binary (0 through 1) to count. The reason for this is based on electrical signals being “ON” (1), or “OFF” (0). Take the (binary) number 01000101 for instance:

Question 4

Subnet Mask

Answer 4

IP addresses actually have two parts. The “Network ID” and “Host ID”. The purpose of the Subnet Mask is to identify which portion of the IP address is the Network ID; the remainder is considered the the Host ID.

Question 5

Network ID and Host (Host-Computer)
PC-12

Answer 5

All computers on the same local subnet/network will share the same
Network: ID, but each computer will have their own unique Host ID.

Question 6

Classless Inter-Domain Routing (CIDR) Notation

Answer 6

“CIDR Notation” is a shorthand way of representing any given IP address with it’s Subnet Mask. Take the following for example:
192.168.0.0/24
The /23 represents the number of bits in the Subnet Mask. That is:

Question 7

Automatic Private IP Addressing (APIPA)

Answer 7

APIPA is a DHCP failover mechanism used by all Microsoft Windows
Operating Systems. When a Windows machine connects to the network, but fails to locate a DHCP server (that is, fails to get assigned an IP address), APIPA takes over and automatically assigns an address in the following range: 169.254.0.0/16
This allows hosts on the same network to be able to communicate with each other in spite of not being assigned an address by a DHCP server.

Question 8

Loopback Addresses

Answer 8

All computers use the address space 127.0.0.0/8 to identify themself. The address range 127.0.0.0 to 127.255.255.254 are referred to as
“loopback” addresses. The loopback address (people typically use 127.0.0.1) allows a computer to confirm that it can use TCP/IP and allows for different programs running on the same machine to communicate with each other using IP. (For example, a domain controller or DNS server.)

Question 9

Private IP Addresses

Answer 9

The Internet Assigned Numbers Authority (IANA) has reserved a specific set of
IP address ranges for private network use. You’ll likely see these assigned to your personal devices whenever you are working from home or an office. The ranges are as follows:

Question 10

Public Address Space

Answer 10

Most of the rest of the remaining IP addresses are considered “public” and can be assigned to devices/servers/endpoints on the internet. There are a few exceptions to this though. You check out the following site to get a list of exceptions: IANA IPv4 Special-Purpose Address Registry

Question 11

IPv4 Addressing & Network Basics(ON EXAM)

Answer 11

• What is an IP Address?
• How to count in, and understand binary (000110100100)
• What is a Subnet Mask and how do they work
• CIDR Notation (Classless Inter-Domain Routing)
• IP Address types (APIPA, Loopback, Private, and Public)