IPv6 subnet calculator

IPv6 CIDR range for fdfd:fdfd::/90

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 fdfd:fdfd::/90

The prefix identifies a network with 38 host bits. Every address from the first address through the last address belongs to this range.

CIDR prefix

fdfd:fdfd::/90

Network mask

ffff:ffff:ffff:ffff:ffff:ffc0::

Prefix length

/90

Host bits

38

First address

fdfd:fdfd::

Last address

fdfd:fdfd::3f:ffff:ffff

Total addresses

274877906944

Total addresses (human readable)

2^38 addresses (274,877,906,944; about 274.87 billion)

How this range is calculated

  1. 1The /90 prefix keeps the first 90 network bits fixed.
  2. 2Setting all 38 host bits to zero produces fdfd:fdfd::.
  3. 3Setting those host bits to one produces fdfd:fdfd::3f: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

fdfd:fdfd:0000:0000:0000:0000:0000:0000

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