IPv6 subnet calculator

IPv6 CIDR range for 2400:cb00:4::/47

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 2400:cb00:4::/47

The prefix identifies a network with 81 host bits. Every address from the first address through the last address belongs to this range.

CIDR prefix

2400:cb00:4::/47

Network mask

ffff:ffff:fffe::

Prefix length

/47

Host bits

81

First address

2400:cb00:4::

Last address

2400:cb00:5:ffff:ffff:ffff:ffff:ffff

Total addresses

2417851639229258349412352

Total addresses (human readable)

2^81 addresses (2,417,851,639,229,258,349,412,352; about 2.41 septillion)

How this range is calculated

  1. 1The /47 prefix keeps the first 47 network bits fixed.
  2. 2Setting all 81 host bits to zero produces 2400:cb00:4::.
  3. 3Setting those host bits to one produces 2400:cb00:5: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

2400:cb00:0004:0000:0000:0000:0000:0000

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