IPv6 subnet calculator

IPv6 CIDR range for ff00:0:0:1::/72

Calculate the network address, final address, mask, and exact address capacity of any IPv6 CIDR prefix.

Example: 2606:4700::/32

Host bits are normalized to the network address before the range is calculated.

CIDR calculation

Network details for ff00:0:0:1::/72

The prefix identifies a network with 56 host bits. Every address from the first address through the last address belongs to this range.

CIDR prefix

ff00:0:0:1::/72

Network mask

ffff:ffff:ffff:ffff:ff00::

Prefix length

/72

Host bits

56

First address

ff00:0:0:1::

Last address

ff00::1:ff:ffff:ffff:ffff

Total addresses

72057594037927936

Total addresses (human readable)

2^56 addresses (72,057,594,037,927,936; about 72.05 quadrillion)

How this range is calculated

  1. 1The /72 prefix keeps the first 72 network bits fixed.
  2. 2Setting all 56 host bits to zero produces ff00:0:0:1::.
  3. 3Setting those host bits to one produces ff00::1:ff:ffff:ffff:ffff.

Network address

The normalized prefix base

CIDR notation describes a network, not a single host. If an address with host bits set is entered, this calculator normalizes it to the network base before calculating the range.

Expanded network address

ff00:0000:0000:0001:0000:0000:0000:0000

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