Documentation prefix
- Input
- 2001:db8:abcd:12::1/64
- Expected output
- 2001:db8:abcd:12::/64
2001:db8::/32 is reserved for documentation.
ipv6 subnet calculator
IPv6 subnet calculator
IPv6 changes subnetting scale: calculation uses 128 bits, long prefixes and no broadcast address.
Approved intentCalculate IPv6 prefix, first/last address and block size.
IPv6 mode in the toolThe Subnet Calculator below already opens in IPv6 mode with `2001:db8:abcd:12::1/64`, ready for you to replace the prefix.
subnetCalculator.ipv6Hint
subnetCalculator.resultLabel
subnetCalculator.network2001:db8:abcd:12::/64
subnetCalculator.firstAddress2001:db8:abcd:12::
subnetCalculator.lastAddress2001:db8:abcd:12:ffff:ffff:ffff:ffff
subnetCalculator.totalAddresses2^64
subnetCalculator.hostBits64
subnetCalculator.typesubnetCalculator.ipv6Types.documentation
subnetCalculator.privacyNote
What changes in IPv6
- The tool normalizes and compresses addresses, applies a 128-bit mask and classifies types such as global, unique-local and documentation.
- IPv6 has no broadcast; output therefore shows first/last address and theoretical block size.
IPv6 examples
Unique local
- Input
- fd00::1/64
- Expected output
- fd00::/64
Common range for private IPv6 networks.
Frequently asked questions
Does IPv6 have dotted masks?
No. IPv6 uses CIDR prefixes such as /64 or /48.
Why is /64 so common?
/64 is the common IPv6 LAN subnet size, especially for SLAAC compatibility.