IPv6 subnet calculator

IPv6 CIDR range for 2001:db8:a800::/42

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:a800::/42

The prefix identifies a network with 86 host bits. Every address from the first address through the last address belongs to this range.

CIDR prefix

2001:db8:a800::/42

Network mask

ffff:ffff:ffc0::

Prefix length

/42

Host bits

86

First address

2001:db8:a800::

Last address

2001:db8:a83f:ffff:ffff:ffff:ffff:ffff

Total addresses

77371252455336267181195264

Total addresses (human readable)

2^86 addresses (77,371,252,455,336,267,181,195,264; about 77.37 septillion)

How this range is calculated

  1. 1The /42 prefix keeps the first 42 network bits fixed.
  2. 2Setting all 86 host bits to zero produces 2001:db8:a800::.
  3. 3Setting those host bits to one produces 2001:db8:a83f: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

2001:0db8:a800:0000:0000:0000:0000:0000

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