IPv6 Calculator¶
Input¶
Enter an IPv6 address with a prefix length (e.g. 2001:db8::/32 or fe80::1/64). Both full and compressed forms are accepted.
Result rows¶
| Row | Description |
|---|---|
| Network (CIDR) | Network address + prefix |
| Prefix Length | e.g. /32 |
| First IP | First address in the block |
| Last IP | Last address in the block |
| Total Addresses | Count (or 2^N for very large blocks) |
| Address Type | Global Unicast / Link-local / Multicast / ULA / Loopback / … |
| Address (Expanded) | Full 128-bit form with all leading zeros |
| Address (Compressed) | RFC 5952 canonical compressed form |
| Reverse DNS Zone | ip6.arpa zone |
Binary / Hex Representation¶
Expand the Binary / Hex Representation panel to see the address in binary (blue = network bits, grey = interface bits) and hexadecimal.
Subnet Splitter¶
Works identically to the IPv4 splitter. For very large splits (prefix difference ≥ 63) the total count is displayed as 2^N.
Overlap Checker¶
The Subnet Overlap Checker is in the Tool Drawer — click the toolbar button on the IPv6 tab. Mixed IPv4/IPv6 pairs are not supported — the checker returns an error ("Cannot compare IPv4 and IPv6 addresses."). See Overlap Checker.
ULA Prefix Generator¶
See IPv6 ULA Generator.
REST API¶
IPv6 subnet calculations are available programmatically via POST /api/v1/ipv6.