Subnetting 1 Total IP Subnetmask | Tutorial Belajar Online Lengkap CISCO CCNA 200-301 Part 10

Summary

In this video, the presenter explains how to determine the most effective IP address and subnet mask for a network. Using a network of 100 PCs, the video focuses on calculating the total number of IPs, subnet mask, network, broadcast, and IP range. The presenter highlights the importance of using private IP addresses for local networks and demonstrates how to configure them in Cisco Packet Tracer. Emphasizing the difference between prefix and subnet mask, the tutorial guides viewers through basic subnetting calculations, offering practical examples and insights for beginners to understand network configuration.

Takeaways

• 😀 The effective prefix for a network with 100 PCs is /25, as it allows for 128 usable IP addresses.
• 😀 Private IP address ranges for LAN networks include 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16.
• 😀 When determining the total number of IPs, you can calculate it by subtracting the prefix from 32 (2^7 = 128 total IPs for /25).
• 😀 Subnet mask and prefix are interchangeable, but the way they are used depends on the vendor (e.g., MikroTik uses prefix, Cisco uses subnet mask).
• 😀 Subnetting is the process of dividing a network into smaller subnetworks, making it easier to manage and use available IP addresses efficiently.
• 😀 The subnet mask for a /25 prefix is 255.255.255.128, determined by subtracting the total IPs (128) from 256.
• 😀 In Cisco Packet Tracer, you configure IP addresses using a subnet mask instead of a prefix.
• 😀 To find the subnet mask for a network, subtract the total IPs from 256. For a /25 prefix with 128 IPs, the subnet mask is 255.255.255.128.
• 😀 The IP address range for the 192.168.0.0 network starts with 0.0, and the last segment of the address (0-255) can vary.
• 😀 Understanding how to calculate network IP, broadcast IP, and IP range is essential for properly configuring a network, and these concepts will be covered in a future video.

Q & A

What is the most effective prefix for 100 PCs?

The most effective prefix for 100 PCs, as calculated in the previous video, is slash 25 (/25).

What is the importance of using private IP ranges in local area networks (LAN)?

In local area networks (LAN), it's crucial to use private IP ranges to ensure security and prevent conflicts with public IP addresses.

What are the available private IP address ranges?

The available private IP address ranges are 10.0.0.0 to 10.255.255.255, 172.16.0.0 to 172.31.255.255, and 192.168.0.0 to 192.168.255.255.

In the example, which private IP address range is being used?

In this example, the private IP address range 192.168.0.0 is being used.

What should we focus on when dealing with IP addresses?

When dealing with IP addresses, the focus should be on the last number of the address, as it will change. The first three numbers (e.g., 192.168) remain constant.

How is the total number of IP addresses calculated for a given prefix?

The total number of IP addresses is calculated by subtracting the prefix from 32 (the total number of bits in an IPv4 address). For a /25 prefix, it’s 32 - 25 = 7, and then 2^7 = 128 total IP addresses.

What is the subnet mask used for in IP configuration?

The subnet mask is used to define the network and host portions of an IP address. It is commonly used instead of the prefix in many configurations, such as with Cisco devices.

How does the subnet mask differ from the prefix in network configurations?

The prefix is often used in configurations by some vendors (like MikroTik), while others (like Cisco) use subnet masks. Both represent the same information, but in different formats.

What is the formula to calculate the subnet mask from the total IP addresses?

To calculate the subnet mask, subtract the total number of IP addresses from 256. For example, if there are 128 IP addresses (as in /25), the subnet mask would be 256 - 128 = 128.

How would the subnet mask appear for a /25 prefix?

For a /25 prefix, the subnet mask would be 255.255.255.128. The first three octets remain 255, and the last octet is 128.