Networking Tools
Use networking tools when you need to calculate ranges, convert masks, classify IP addresses, or prepare reverse DNS zones.
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Calculate A Network Range
Start here when you need usable host counts, subnet masks, network boundaries, or broadcast details.
Classify An IP Address
Use the IP checker when you need to confirm whether an address is public, private, or otherwise special-use.
Prepare Reverse DNS
Generate the correct reverse naming format before creating PTR records or reverse zones.
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Networking Tools
Subnet Calculator
Calculate network range, usable hosts, subnet mask, broadcast address, and more.
Private vs Public IP Checker
Check whether an IPv4 address is private, public, or special-use.
CIDR ↔ Subnet Mask Converter
Convert between CIDR notation and dotted-decimal subnet masks.
Reverse PTR Zone Helper
Generate reverse PTR record format and suggested reverse DNS zone names.
Featured Articles
Private vs Public IP Addresses Explained
Learn the difference between private and public IP addresses, how special-use ranges fit in, and why correct IP classification matters in troubleshooting.
What Is a Dangling CNAME?
Learn what a dangling CNAME is, why it can create subdomain takeover risk, what patterns to look for, and how to clean up stale aliases safely.
CIDR Cheat Sheet for Common Subnet Sizes
Use this CIDR cheat sheet to quickly compare common subnet sizes, masks, block sizes, and usable host counts during subnet planning and troubleshooting.
How to Calculate a Subnet Range Step by Step
A practical guide to calculating network address, broadcast address, and usable host range from an IP address and subnet size.
What Is a Subnet Mask? Explained Clearly
Learn what a subnet mask does, how it separates network and host portions of an IPv4 address, and how it relates to CIDR and usable ranges.
What Is CIDR Notation? Explained with Examples
Learn what CIDR notation means, how slash prefixes like /24 and /27 define IP ranges, and how CIDR relates to subnet masks and routing.