Concept
IPv6 addresses contain 128 bits. A prefix identifies the network portion; IPv6 has no broadcast address, and large ranges must be represented mathematically rather than enumerated. The calculator accepts compressed and expanded notation.
Worked example
2001:db8:1234:5678::10/64
Network prefix: 2001:db8:1234:5678::/64
Interface identifier: ::10
Capacity: 18,446,744,073,709,551,616 addresses
IPv6 has no broadcast address. The /64 prefix identifies the network and the remaining 64 bits identify addresses within it.Common planning boundaries
/32, /48, /56, /60, and /64 are common planning boundaries. They are conventions and allocation practices, not a replacement for the requirements of a particular design.
Try it yourself
Use the IPv6 calculator to inspect compressed, expanded, and network-prefix forms.