IP SUBNETING

Summary

In this lecture, the topic of subnetting is explored, focusing on its importance in addressing the challenges posed by the rapid growth of internet domains and IP address depletion. The video explains the history of IP address usage, the problems arising from domain expansion, and how subnetting optimizes IP address allocation. Concepts such as CIDR, class-based IP addresses, and practical subnetting calculations are discussed. The lecture emphasizes the role of subnetting in improving network performance, reducing traffic, and managing large-scale networks efficiently.

Takeaways

• 😀 The number of internet domains has increased dramatically since 1991, from 20 million to 180 million by 2022, straining available IP addresses.
• 😀 Subnetting is a crucial technique used to manage and optimize the allocation of IP addresses in large-scale networks.
• 😀 The rapid expansion of networks and the increasing number of connected devices were not anticipated when TCP/IP was first designed for laboratory use.
• 😀 IP address shortages can slow down the growth of the internet, making it necessary to implement solutions like subnetting or supernetting.
• 😀 Subnetting helps reduce network traffic, improve performance, and simplify network management, especially in geographically distributed networks.
• 😀 Network address management is essential to prevent overhead from large routing tables, which can slow down the exchange of information.
• 😀 A subnet mask is used to define the boundaries of a network, and the size of a network is determined by the class (A, B, or C) of the IP address.
• 😀 For networks with fewer devices, class C subnet masks are used, while larger networks may require class A or B subnet masks.
• 😀 The formula to calculate the number of subnets is 2^n - 2, where 'n' is the number of bits used for subnetting.
• 😀 Subnetting can lead to more efficient use of IP addresses by dividing a single large network into several smaller subnets, each with a limited number of hosts.
• 😀 Practical examples demonstrate how subnetting allows IP addresses to be distributed efficiently across multiple subnets, ensuring optimal network performance.

Q & A

What is the primary purpose of subnetting in IP address management?

The primary purpose of subnetting is to efficiently allocate and conserve IP addresses within a network by dividing a single network into smaller sub-networks (subnets), allowing more effective use of the available address space.

Why did the original designers of TCP/IP not anticipate the rapid growth of networked devices?

The original designers of TCP/IP only envisioned its use in a laboratory setting, so they didn’t foresee the massive expansion of networks and connected devices that would occur over time, leading to the need for address conservation.

How has the number of internet domains changed from 1991 to 2022?

The number of internet domains increased dramatically from around 20 million in 1991 to 180 million by early 2022, and this growth is expected to continue, significantly impacting the demand for IP addresses.

What are some of the challenges associated with the rapid growth of internet domains?

The rapid growth of internet domains leads to issues like limited IP address availability, large routing tables that burden routers, and increased administrative overhead, all of which can slow down network performance.

What is Classless Inter-Domain Routing (CIDR) and how does it help in IP address conservation?

CIDR is a method used to allocate IP addresses more flexibly and efficiently. It allows for variable-length subnet masks (VLSM), enabling networks to be divided into smaller subnets and reducing waste of IP addresses.

Why is it important to manage IP address allocation carefully in the context of network growth?

As the number of connected devices grows, careful management of IP address allocation ensures there are enough available addresses for all devices without exhausting the address pool, which would lead to network failures.

How does subnetting improve network performance?

Subnetting reduces network traffic by segmenting a large network into smaller, more manageable subnets. This helps to isolate network traffic, reduce congestion, and improve overall network performance.

What are some key advantages of subnetting in large networks?

Subnetting offers several advantages, including easier network management, reduced traffic congestion, optimized performance, and the ability to separate large geographically dispersed networks into smaller, more manageable segments.

How is the number of subnets and hosts in a network calculated using subnet masks?

The number of subnets can be calculated using the formula 2^n - 2, where 'n' is the number of bits borrowed for subnetting. The total number of hosts per subnet is calculated by multiplying the number of subnets by the number of available host addresses within each subnet.

What is the significance of using a subnet mask in the subnetting process?

A subnet mask is crucial in identifying the boundary between the network portion and the host portion of an IP address. It helps in defining the size of a subnet and determining which IP addresses belong to the same network.