IPv6 subnet calculator

IPv6 CIDR range for fd05::/126

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 fd05::/126

The prefix identifies a network with 2 host bits. Every address from the first address through the last address belongs to this range.

CIDR prefix

fd05::/126

Network mask

ffff:ffff:ffff:ffff:ffff:ffff:ffff:fffc

Prefix length

/126

Host bits

2

First address

fd05::

Last address

fd05::3

Total addresses

4

Total addresses (human readable)

2^2 addresses (4)

How this range is calculated

  1. 1The /126 prefix keeps the first 126 network bits fixed.
  2. 2Setting all 2 host bits to zero produces fd05::.
  3. 3Setting those host bits to one produces fd05::3.

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

fd05:0000:0000:0000:0000:0000:0000:0000

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