IPv6 subnet calculator

IPv6 CIDR range for 2001:db8::64/126

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 2001:db8::64/126

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

2001:db8::64/126

Network mask

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

Prefix length

/126

Host bits

2

First address

2001:db8::64

Last address

2001:db8::67

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 2001:db8::64.
  3. 3Setting those host bits to one produces 2001:db8::67.

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

2001:0db8:0000:0000:0000:0000:0000:0064

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