Network Comparison Fields
Valid Network Required
Valid Network Required
Subnet Overlap Checker
Network overlaps are a leading cause of routing failures and VPN drops. Our checker allows you to compare two CIDR blocks or a single IP against a subnet to identify conflicts before they happen. Perfect for safe VPC peering, cloud migrations, and cleaning up complex firewall rules.
Conflict Detection
VPC Peering Ready
Routing Safety
How to Use the Subnet Overlap Checker
What is Subnet Overlapping?
Subnet overlap occurs when two network ranges share one or more IP addresses. In networking, overlapping subnets cause routing conflicts because a router won't know which physical or virtual path to send traffic to. This tool helps you identify these conflicts before they break your VPC peering, VPN tunnels, or local VLANs.
Step-by-Step Overlap Detection
- 1Enter First Network: Provide the first CIDR block or IP address in the Network 1 field (e.g.,
10.0.0.0/16). - 2Enter Second Network: Provide the range you want to compare against in the Network 2 field (e.g.,
10.0.50.0/24). - 3Detect Range: You can also enter a single IP (e.g.,
192.168.1.55) in one field to see if it falls within a larger subnet entered in the other. - 4Analyze Results: Click "Check For Overlap." The tool will generate a status banner (Safe, Warning, or Danger) and a comparison table showing the exact Start and End IP boundaries for both targets.
Understanding the Status Results:
| Status | Meaning | Action Required |
|---|---|---|
| Safe | Ranges are completely separate. | None. Safe to peer/route. |
| Subset | One network is inside the other. | Review routing priority (LPM). |
| Partial | Networks share some IPs. | Change one network prefix. |
| Match | Both ranges are identical. | Critical conflict. Change one. |