Multiple Subnets and VLSM Planning

This page helps you review several IPv4 networks together so you can compare masks, ranges, and address use without changing the existing textarea or result grid.

Inputs explained

Enter one CIDR block per line. The tool reads each network separately and summarizes the results together for easier planning.

How it works

Each subnet is parsed into its numeric boundary, then the page calculates masks, usable ranges, and related summary values for the full list.

Calculate Multiple Subnets

Enter one or more networks (CIDR), comma or newline separated.

Results

Step-by-Step Example

Paste several branch or VLAN subnets into the box and compare the resulting address ranges. This makes it easier to spot wasted space, mismatched masks, or inconsistent planning decisions.

Use Cases

Use this page for VLSM planning, branch design, address inventory review, and training exercises.

Assumptions and limitations

The output is subnet math. Reservations and operational policy still need separate review.

Frequently Asked Questions

What does the multiple subnets tool do?

It helps plan several IPv4 subnets together so you can review boundaries, masks, and address use across a set of networks.

When is this useful?

It is useful for VLSM planning, branch network design, lab exercises, and reviewing whether multiple prefixes fit an allocation cleanly.

What limitations apply to the output?

The output is subnet math only. It does not know reservations, gateway policy, or platform specific design constraints.