SUBNETTING VLSM

Summary

In this video, Muhammad Lutfi Hamzah continues the discussion on subnetting, focusing on Variable-Length Subnet Masking (VLSM). He explains how VLSM allows for efficient IP address allocation based on specific needs of different buildings. The tutorial includes practical examples of calculating IP ranges, subnet masks, and broadcast addresses for multiple buildings, including the necessary prefix lengths for optimal IP distribution. Viewers are guided through the process step-by-step, enhancing their understanding of subnetting techniques to ensure effective network management.

Takeaways

• 😀 VLSM (Variable Length Subnet Mask) allows for efficient IP address allocation based on specific needs.
• 📊 Different subnet masks can be used for various buildings to optimize the use of available IP addresses.
• 🏢 Each building's IP allocation is tailored to its requirements, avoiding wastage of IP addresses.
• 🔍 Understanding CIDR (Classless Inter-Domain Routing) prefixes is essential for selecting appropriate subnet masks.
• 📈 A building requiring 1000 IP addresses can use a /22 prefix, providing 1024 usable addresses.
• 💻 For 500 IP addresses, a /23 prefix is appropriate, allowing for 512 usable addresses.
• 📞 For 100 IP addresses, a /25 prefix is suitable, enabling the allocation of 126 usable addresses.
• 📡 Network addresses and broadcast addresses are crucial in determining the range of usable IPs.
• 🖥️ Each subnet must ensure that IP addresses do not overlap between buildings for proper network functioning.
• 🌐 VLSM is an effective strategy for managing and optimizing IP address usage in a network.

Q & A

What is VLSM and why is it used?

VLSM, or Variable Length Subnet Masking, is a technique that allows the allocation of IP addresses based on the specific requirements of each segment or building, rather than using a fixed-size subnet. This increases IP address efficiency.

How does the prefix notation work in subnetting?

Prefix notation, or CIDR (Classless Inter-Domain Routing), indicates the number of bits used for the subnet mask. For example, a prefix of /22 means that the first 22 bits are used for the network portion of the address, leaving the remaining bits for host addresses.

What subnet mask corresponds to a prefix of /22?

The subnet mask corresponding to a prefix of /22 is 255.255.252.0, which allows for 1,022 usable IP addresses.

How many IP addresses does Building A require and what prefix is allocated to it?

Building A requires 1,000 IP addresses and is allocated a prefix of /22.

What is the significance of the network address and broadcast address?

The network address is the first address in a subnet, used to identify the subnet itself, while the broadcast address is the last address, used to send data to all hosts within that subnet.

What prefix is used for Building B and how many IP addresses does it support?

Building B is allocated a prefix of /23, which supports up to 510 usable IP addresses.

How do you calculate the first usable IP address in a subnet?

The first usable IP address is calculated by adding 1 to the network address. For example, if the network address is 172.16.0.0, the first usable IP would be 172.16.0.1.

What prefix is allocated to the server room and how many IP addresses does it allow?

The server room is allocated a prefix of /30, which allows for 2 usable IP addresses.

Why is it important to use VLSM in IP allocation?

Using VLSM is important because it optimizes the use of IP addresses, allowing organizations to allocate exactly the number of addresses needed for each segment, reducing waste and improving network efficiency.

What steps are involved in determining the range of IP addresses for a building?

To determine the range of IP addresses for a building, you first identify the network address and its corresponding subnet mask. Then, you calculate the broadcast address and identify the usable IP addresses between the network address and the broadcast address.