IP addressing
Calculate, expand, merge, and normalize IPv4 or IPv6 address data.
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Tool category
Network
Prepare and review network values before applying them to firewalls, cloud consoles, documentation, or support tickets. The utilities expose the calculated ranges and normalized output for manual verification.
10 tools
Choose a task
IP, DNS, ports, and network diagnostics.
IPv4 Subnet Calculator
Calculate CIDR blocks, masks, ranges, and broadcast addresses locally.
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IPv4 Address Converter
Convert IPv4 addresses to decimal, hexadecimal, binary, and IPv6-mapped forms.
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IPv4 Range Expander
Find the smallest CIDR block that covers a start and end IPv4 address.
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CIDR Merger
Merge IPv4 addresses and CIDR blocks into a smaller allowlist.
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DNS Record Helper
Build common DNS records and copy ready-to-paste zone lines.
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IP Allowlist Builder
Normalize IPs, CIDR blocks, and ranges into copyable allowlists.
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Domain Info Helper
Extract, normalize, deduplicate, and export domains with a DNS and WHOIS checklist.
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MAC Address Lookup
Normalize MAC addresses, inspect flags, and look up vendors locally.
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MAC Address Generator
Generate formatted local unicast MAC addresses for tests and VMs.
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IPv6 ULA Generator
Generate RFC 4193 local IPv6 ULA prefixes and /64 blocks.
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Workflows
Network operations
Prepare DNS records, allowlists, domain notes, and MAC address values.
Quick answers
Do calculations replace a network change review?
No. Confirm routing, exclusions, address family, provider syntax, and blast radius before applying output.