IPv4 Address Types (obj 1.5)

Question 1

What is a Public IPV4 Address?

Answer 1

Also known as routable IP address, it is a unique identifier assigned to devices on the internet. Must be leased or purchased from Internet Service Providers (ISPs) and is globally managed by ICANN.

ICANN stands for Internet Corporation for Assigned Names and Numbers.

Question 2

What are Regional Internet Registries (RIRs)?

Answer 2

Responsible for managing public IP addresses for different regions, including:
* ARIN – North America
* LACNIC – Latin America
* AFNIC – Africa
* APNIC – Asia Pacific
* RIPE – Europe

Each RIR manages IP address allocations in its respective region.

Question 3

What is a Private IPV4 Address?

Answer 3

A non-internet routable IP address used within local networks, allowing communication between devices without using a public IP address.

Can be used by anyone at any time, but only within their own LANs.

Question 4

What is Network Address Translation (NAT)?

Answer 4

A method used to translate private IP addresses into public IP addresses and vice versa, facilitating communication between local and public networks, and helping conserve global IP address space.

NAT is often used in routers to manage private networks.

Question 5

What is Request for Comments (RFC)?

Answer 5

A formal publication from the Internet Engineering Task Force (IETF), authored by individuals or groups of computer scientists to document new technologies or standards they are proposing.

RFCs serve as a mechanism for sharing information and standards in the internet community.

Question 6

What does RFC 1918 define?

Answer 6

Defines ranges for private IP addresses including:
* Class A – 10.x.x.x (e.g., 10.0.0.0 - 10.255.255.255)
* Class B – 172.16.x.x to 172.31.x.x (e.g., 172.16.0.0 - 172.31.255.255)
* Class C – 192.168.x.x (e.g., 192.168.0.0 - 192.168.255.255)

These ranges are reserved for private networks and cannot be routed on the public internet.

Question 7

What is the Loopback Address?

Answer 7

A specialized IP address assigned as 127.0.0.1, used for internal testing and troubleshooting, allowing higher-level protocols to send data back to the host itself.

The entire 127.x.x.x range is reserved for loopback purposes.

Question 8

What is Automatic Private IP Addressing (APIPA)?

Answer 8

Dynamically assigned by an OS when a DHCP server is unavailable, with a range of 169.254.0.0 to 169.254.255.255, used as a fallback for network configurations.

Indicates a DHCP issue if assigned to a device.

Question 9

What is Dynamic Host Configuration Protocol (DHCP)?

Answer 9

Assigns dynamic IP addresses to devices through a process known as DORA, which stands for:
* Discovery
* Offer
* Request
* Acknowledgment

DHCP automates the process of IP address assignment to devices on a network.

Question 10

What are key exam tips regarding IP addresses?

Answer 10

Understand distinctions between public and private IP addresses, memorize ranges for private IP addresses (RFC 1918), be aware of loopback/local host and APIPA addresses, and recognize DHCP issues indicated by APIPA addresses.

These tips are crucial for mastering networking concepts and performing well in exams.