IPv4 Range to CIDR Expander Online
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Cloud consoles and firewall rules often ask for CIDR when all you have is a start and end address. Enter both ends of your range and get the enclosing CIDR notation, the expanded start and end, and how many addresses you gain by rounding up to a block boundary.
How it works
- 1
Enter start and end
Two plain IPv4 addresses define your range.
- 2
Read the enclosing CIDR
The tool rounds your range up to the nearest block boundary.
- 3
Compare sizes
See the original address count next to the expanded one.
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