IPv6 subnet calculator

IPv6 CIDR range for ::/0

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 ::/0

The prefix identifies a network with 128 host bits. Every address from the first address through the last address belongs to this range.

CIDR prefix

::/0

Network mask

::

Prefix length

/0

Host bits

128

First address

::

Last address

ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff

Total addresses

340282366920938463463374607431768211456

Total addresses (human readable)

2^128 addresses (340,282,366,920,938,463,463,374,607,431,768,211,456; about 340.28 undecillion)

How this range is calculated

  1. 1The /0 prefix keeps the first 0 network bits fixed.
  2. 2Setting all 128 host bits to zero produces ::.
  3. 3Setting those host bits to one produces ffff:ffff:ffff:ffff:ffff: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

0000:0000:0000:0000:0000:0000:0000:0000

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