1. What is CIDR Subnetting?

CIDR (Classless Inter-Domain Routing) subnetting is a method for allocating IP addresses and routing Internet Protocol packets. It allows for more efficient use of IP address space by breaking larger networks into smaller subnets.

2. How Does the Calculator Work?

The calculator uses the CIDR subnet formula:

Where:

• \( \text{New Prefix} \) — The subnet mask length in bits for the new subnets
• \( \text{Old Prefix} \) — The original network mask length in bits

Explanation: The difference between the new and old prefix lengths determines how many bits are available for subnetting. Each additional bit doubles the number of possible subnets.

3. Importance of Subnet Calculation

Details: Proper subnet calculation is essential for network design, efficient IP address allocation, and maintaining network security through segmentation.

4. Using the Calculator

Tips: Enter the original network prefix length and the new subnet prefix length. The new prefix must be equal to or larger than the original prefix (between 1-32 bits).

5. Frequently Asked Questions (FAQ)

Q1: What's the maximum number of subnets possible?
A: With a /32 prefix, you can have up to 2^(32 - original_prefix) subnets, though practical limits are much lower.

Q2: How does this relate to host addresses per subnet?
A: Hosts per subnet = 2^(32 - new_prefix) - 2 (for network and broadcast addresses).

Q3: Can I subnet a /24 network into /23 subnets?
A: No, the new prefix must be larger (smaller number) than the original to create subnets.

Q4: What's the smallest possible subnet?
A: A /32 is a single host address (point-to-point link).

Q5: How does VLSM differ from this calculation?
A: VLSM allows different subnet sizes within the same network, while this calculator assumes equal-sized subnets.