IPv6 subnet calculator

IPv6 CIDR range for 2000::/3

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::/3

The prefix identifies a network with 125 host bits. Every address from the first address through the last address belongs to this range.

CIDR prefix

2000::/3

Network mask

e000::

Prefix length

/3

Host bits

125

First address

2000::

Last address

3fff:ffff:ffff:ffff:ffff:ffff:ffff:ffff

Total addresses

42535295865117307932921825928971026432

Total addresses (human readable)

2^125 addresses (42,535,295,865,117,307,932,921,825,928,971,026,432; about 42.53 undecillion)

How this range is calculated

  1. 1The /3 prefix keeps the first 3 network bits fixed.
  2. 2Setting all 125 host bits to zero produces 2000::.
  3. 3Setting those host bits to one produces 3fff: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

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