About ipv6 calculator
IPv6 addresses are 128 bits written as eight groups of hex digits. They can be shortened by dropping leading zeros and replacing one run of zero groups with ::.
Example
2001:0db8:0000:0000:0000:0000:0000:0001 shortens to 2001:db8::1.
Address types
- ::1 is loopback.
- fe80::/10 is link-local.
- fc00::/7 is unique local (private).
- 2000::/3 is global unicast (public).
Runs in your browser
Calculations on this page happen on your device. Nothing you enter is uploaded.
A worked example
2001:0db8:0000:0000:0000:0000:0000:0001 compresses to 2001:db8::1, because the leading zeros are dropped and one run of zero groups is replaced by ::. The prefix 2001:db8::/32 is reserved for documentation, so you will see it in examples.
Subnetting
- A typical site is given a /48 and splits it into /64 networks.
- A single /64 holds 2^64 addresses, which is the square of the entire IPv4 address space.
- Do not subnet smaller than /64 for ordinary LANs.
Writing rules
Hex digits are case-insensitive, though lowercase is recommended. Only one :: may appear in an address, and URLs put an IPv6 address in square brackets.
