IPv6 subnet calculator

IPv6 CIDR range for 2000::/6

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 2000::/6

The prefix identifies a network with 122 host bits. Every address from the first address through the last address belongs to this range.

CIDR prefix

2000::/6

Network mask

fc00::

Prefix length

/6

Host bits

122

First address

2000::

Last address

23ff:ffff:ffff:ffff:ffff:ffff:ffff:ffff

Total addresses

5316911983139663491615228241121378304

Total addresses (human readable)

2^122 addresses (5,316,911,983,139,663,491,615,228,241,121,378,304; about 5.31 undecillion)

How this range is calculated

  1. 1The /6 prefix keeps the first 6 network bits fixed.
  2. 2Setting all 122 host bits to zero produces 2000::.
  3. 3Setting those host bits to one produces 23ff: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

2000:0000:0000:0000:0000:0000:0000:0000

Recent network calculations

Recent IPv6 CIDR Ranges

Open recent IPv6 prefixes to inspect their normalized range, mask, and address capacity.

Learn how IPv6 CIDR notation and subnet ranges work