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IPv6 CIDR Calculator

The IPv6 CIDR to Range tool provides the start and end IPv6 address for an IPv6 address range using CIDR notation.

Enter an IPv6 address with CIDR:

About this Tool

The IPv6 CIDR to Range tool will specifically show you the start and end IPv6 address in the range, as well as the number of hosts.

What is CIDR? Classless Inter-Domain Routing (CIDR) is an expansion of the IP addressing system that allows for a more efficient and appropriate allocation of addresses. CIDR changed fixed fields into variable-length fields, allowing addresses to be assigned with more granularity. The CIDR IP address includes a number that tells how the address is split between networks and hosts. For example, in the CIDR address the /20 indicates that the first 20 bits are used for network ID and the remaining 12 (there are 32 bits in the IP address) are used for host ID.