IPv6 subnet calculator

IPv6 CIDR range for ::/1

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 ::/1

The prefix identifies a network with 127 host bits. Every address from the first address through the last address belongs to this range.

CIDR prefix

::/1

Network mask

8000::

Prefix length

/1

Host bits

127

First address

::

Last address

7fff:ffff:ffff:ffff:ffff:ffff:ffff:ffff

Total addresses

170141183460469231731687303715884105728

Total addresses (human readable)

2^127 addresses (170,141,183,460,469,231,731,687,303,715,884,105,728; about 170.14 undecillion)

How this range is calculated

  1. 1The /1 prefix keeps the first 1 network bits fixed.
  2. 2Setting all 127 host bits to zero produces ::.
  3. 3Setting those host bits to one produces 7fff: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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