NETWORKING · CIDR & SUBNETS

Visual CIDR & Subnet Overlap Matrix

Detect IP range collisions across AWS VPCs, Kubernetes clusters, and VPN meshes, visualize tree partitions, and calculate available free subnet allocations.

CIDR Blocks Input

Enter comma-separated or newline-separated IPv4 or IPv6 CIDR blocks (e.g. 10.0.0.0/16, 10.0.32.0/20).

1-Click Presets:

Analysis Results & Diagnostics

ERR_OVERLAP_COLLISION

Subnet Overlap Collision

Subnets 10.0.0.0/16 and 10.0.32.0/20 overlap in address range 10.0.32.0 - 10.0.47.255.

WARN_CONTAINMENT

Parent-Child Containment

10.0.0.0/16 completely encompasses smaller subnet 10.0.32.0/20.

Subnet Overlap Collisions (1)

Subnet A Subnet B Overlapping IP Range
10.0.0.0/16 10.0.32.0/20 10.0.32.0 - 10.0.47.255 (10.0.32.0/20)

2D Subnet Tree Partition Matrix

10.0.0.0/16 collision
Range: 10.0.0.0 - 10.0.255.255
Total Hosts: 65536
10.0.32.0/20 collision
Range: 10.0.32.0 - 10.0.47.255
Total Hosts: 4096

Frequently Asked Questions

What is CIDR overlap collision?

CIDR overlap occurs when two or more network subnets share one or more IP addresses, leading to routing conflicts in VPC peering, Kubernetes pods/services, or VPN connections.

How does free subnet allocation work?

Given a parent block and target prefix size, the algorithm scans for the first contiguous IP block of that size that does not overlap with any existing assigned subnets.