Use this network utility to parse, normalize, convert, or derive IPv4, IPv6, subnet, reverse-DNS, or MAC addressing information under a stated prefix convention.

Address

Dotted-decimal IPv4 address.

Check whether an IPv4 address is private, loopback, or link-local per RFC 1918 and RFC 3927. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Is private

Whether the address is in a checked private or special-use range.

• Syntax and arithmetic validity do not establish reachability, ownership, routing, DNS, privacy, or authorization. IPv4 special-use ranges, IPv6 scopes and compression, prefix boundaries, mapped forms, and host-count conventions require explicit handling.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Validate against current IANA registries and the target platform, test boundary prefixes, and use live network tools only with appropriate authorization.

• EUI-64 IPv6 Link-Local Address Builder

  Derive a modified EUI-64 IPv6 link-local address from a 48-bit MAC by inserting FF:FE and flipping the universal/local bit. Privacy-address schemes use a different method.

• IPv4 Broadcast Address Calculator

  Compute an IPv4 broadcast address from an address and subnet mask.

• IPv4 CIDR Calculator

  Compute network address, broadcast, host range, and capacity for an IPv4 CIDR block.