IPv6 subnet calculator

IPv6 CIDR range for fd00::/77

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 fd00::/77

The prefix identifies a network with 51 host bits. Every address from the first address through the last address belongs to this range.

CIDR prefix

fd00::/77

Network mask

ffff:ffff:ffff:ffff:fff8::

Prefix length

/77

Host bits

51

First address

fd00::

Last address

fd00::7:ffff:ffff:ffff

Total addresses

2251799813685248

Total addresses (human readable)

2^51 addresses (2,251,799,813,685,248; about 2.25 quadrillion)

How this range is calculated

  1. 1The /77 prefix keeps the first 77 network bits fixed.
  2. 2Setting all 51 host bits to zero produces fd00::.
  3. 3Setting those host bits to one produces fd00::7: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

fd00:0000:0000:0000:0000:0000:0000:0000

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