IPv6 subnet calculator

IPv6 CIDR range for fec0::/89

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 fec0::/89

The prefix identifies a network with 39 host bits. Every address from the first address through the last address belongs to this range.

CIDR prefix

fec0::/89

Network mask

ffff:ffff:ffff:ffff:ffff:ff80::

Prefix length

/89

Host bits

39

First address

fec0::

Last address

fec0::7f:ffff:ffff

Total addresses

549755813888

Total addresses (human readable)

2^39 addresses (549,755,813,888; about 549.75 billion)

How this range is calculated

  1. 1The /89 prefix keeps the first 89 network bits fixed.
  2. 2Setting all 39 host bits to zero produces fec0::.
  3. 3Setting those host bits to one produces fec0::7f: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

fec0:0000:0000:0000:0000:0000:0000:0000

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