How IP Addresses Work | Network Fundamentals Part 4

Summary

This video explains the basics of IP addressing, focusing on IPv4. It covers the structure of an IP address, breaking it into octets and exploring how network and host addresses are divided. The video also discusses different IP address classes (A, B, and C) and introduces subnetting, which allows for more efficient use of IP addresses. Viewers will learn about CIDR notation and subnet masks, as well as concepts like supernetting and how routers help devices in different networks communicate. The video is ideal for those looking to understand IP addressing fundamentals and its evolution in modern networking.

Takeaways

• 😀 IP addresses are essential for identifying devices and networks, ensuring data can be sent to the correct destination.
• 😀 An IP address consists of four octets, each representing an 8-bit value, ranging from 0 to 255.
• 😀 Understanding binary is crucial for IP addressing, as each octet is an 8-bit value.
• 😀 An IP address is composed of two parts: the network address and the host address, which help identify both the device and the network it belongs to.
• 😀 IP addressing initially used a class-based system (Class A, B, C, etc.), with each class having different rules for dividing the network and host parts of the address.
• 😀 Class A networks are for large networks, with the first octet indicating the network, and the remaining three octets for host addresses.
• 😀 Class B networks use the first two octets for the network address and the remaining two for host addresses, supporting medium-sized networks.
• 😀 Class C networks use the first three octets for the network address and the last octet for host addresses, suitable for smaller networks.
• 😀 The Class A, B, and C system was replaced by Classless Inter-Domain Routing (CIDR) in 1993, which introduced the concept of subnet masks for more efficient IP address management.
• 😀 Subnet masks are used to divide a network into smaller subnets, with the subnet mask indicating which part of the IP address is for the network and which part is for hosts.
• 😀 CIDR notation simplifies the representation of IP addresses and subnet masks, using a slash followed by the number of network bits (e.g., 192.168.1.0/24).

Q & A

What is an IP address and why is it important?

An IP address is a unique identifier for a device on a network. It is essential because it tells other devices where to send data, whether the device is on a local network or across the globe.

What are the two versions of IP addresses?

The two versions of IP addresses are IPv4 and IPv6. IPv4 is older and more common, while IPv6 is newer and used to address the growing demand for IP addresses.

What is an octet in an IPv4 address?

An octet is one of the four numbers in an IPv4 address. Each octet is an 8-bit value, ranging from 0 to 255. Together, four octets form the complete 32-bit IPv4 address.

Why are IP addresses written in decimal instead of binary?

IP addresses are written in decimal to make them more human-readable. The four octets of an IP address represent 32 bits, but writing them in decimal makes it easier for people to work with.

What is the difference between a network address and a host address in an IP address?

In an IP address, the network address identifies the network to which a device belongs, while the host address identifies the specific device within that network.

What is the purpose of a router in IP networking?

A router is responsible for forwarding data packets between different networks. If devices in different IP networks need to communicate, a router is required to direct the traffic between them.

What are the five classes of IP addresses, and which ones are used for addressing devices?

The five classes of IP addresses are A, B, C, D, and E. Classes A, B, and C are used for addressing devices, with Class A supporting large networks, Class B for medium-sized networks, and Class C for smaller networks. Class D is used for multicast, and Class E is reserved for special purposes.

How does subnetting work, and why is it used?

Subnetting is the practice of dividing a large network into smaller, more manageable sub-networks. It helps efficiently utilize IP address space and improve network performance by reducing traffic within each subnet.

What is CIDR (Classless Inter-Domain Routing), and how does it differ from classful addressing?

CIDR is a method of IP addressing that eliminates the reliance on predefined address classes (A, B, C). It uses subnet masks to specify the network and host portions of an address. This allows for more flexible and efficient use of IP address space compared to classful addressing.

What is the significance of the subnet mask in IP addressing?

The subnet mask defines which portion of an IP address is used for the network and which part is used for hosts. It is used in both classful and classless addressing to divide a network into smaller subnets.