Lec-45: Find Range, Network Id, Host, Broadcast address with Numerical Examples in Hindi

Summary

In this video, the concept of Classful IP Addressing is explained in detail, specifically focusing on Class C addresses. The tutorial guides viewers step-by-step on how to solve related questions commonly found in exams like GATE, UGC-NET, and Banking. Key concepts such as identifying the class of an IP address, calculating the Network ID, determining host IPs, and understanding broadcast addresses are covered. The video also explains the difference between limited and direct broadcast addresses, emphasizing how to calculate and use them correctly. This explanation aims to clarify the process of solving IP Addressing questions efficiently and accurately.

Takeaways

• 😀 Classful IP Addressing is important for solving network-related questions in exams like GATE, UGC-NET, and Banking exams.
• 😀 The first step in solving an IP Addressing problem is to determine the class of the IP address by examining its first octet.
• 😀 Class C IP addresses fall within the range 192 to 223, and this range is crucial to identifying the class.
• 😀 To calculate the Network ID in Class C, use the default subnet mask (255.255.255.0) and perform a bitwise AND operation with the given IP address.
• 😀 In Class C, the last octet of the IP address is used to represent hosts, with a total of 256 possible addresses, but two addresses are reserved (network and broadcast).
• 😀 The 4th host in a Class C network can be found by counting from the network address, and in this example, it is 201.20.30.4.
• 😀 The first address in the last octet (0) is reserved for the Network ID, and the last address (255) is reserved for the broadcast address, so these cannot be used for hosts.
• 😀 The last usable host address in a Class C network is one less than the broadcast address, which in this case is 201.20.30.254.
• 😀 Broadcast addresses come in two types: limited broadcast (255.255.255.255) for sending messages within the same network, and direct broadcast (e.g., 201.20.30.255) for broadcasting to all devices in a different network.
• 😀 Direct broadcast addresses are calculated by setting the last octet to 255, making the last IP address in the network the direct broadcast address.

Q & A

What is the first step in solving an IP Addressing problem when only the IP address is provided?

The first step is to identify the class of the IP address (Class A, B, or C) by examining the first octet.

How do you determine which class an IP address belongs to?

You determine the class of an IP address by checking its first octet. For Class C, the first octet is between 192 and 223.

What is the default subnet mask for Class C addresses?

The default subnet mask for Class C addresses is 255.255.255.0.

What is the significance of the first octet when identifying the class of an IP address?

The first octet determines the class of the IP address. For Class C, the first octet must be in the range of 192-223.

What is the method used to calculate the Network ID in Class C IP addressing?

To calculate the Network ID, perform a bitwise AND operation between the IP address and the default subnet mask. In Class C, the mask is 255.255.255.0.

Why is the value of the first and last host addresses excluded in a Class C network?

The first host address (Network ID) and the last host address (Broadcast Address) are reserved and cannot be assigned to individual hosts.

How can you identify the 4th host in a Class C network?

The 4th host in a Class C network will have the last octet as 4 (e.g., 201.20.30.4). The first octet and network portion remain unchanged.

What is the broadcast address for a Class C network?

The broadcast address for a Class C network is the last IP address of the network, which is the IP with the last octet set to 255 (e.g., 201.20.30.255).

What is the difference between a limited broadcast address and a direct broadcast address?

A limited broadcast address (255.255.255.255) is used for broadcasting within a local network, while a direct broadcast address targets a specific network from an external source, using the last IP address of that network (e.g., 201.20.30.255).

Why is the direct broadcast address important in networking?

The direct broadcast address is important because it allows a message to be broadcasted to all hosts in a specific network from another network or a remote host.