IPv6 subnet calculator

IPv6 CIDR range for fd00::fff8:0:0:0/80

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 fd00::fff8:0:0:0/80

The prefix identifies a network with 48 host bits. Every address from the first address through the last address belongs to this range.

CIDR prefix

fd00::fff8:0:0:0/80

Network mask

ffff:ffff:ffff:ffff:ffff::

Prefix length

/80

Host bits

48

First address

fd00::fff8:0:0:0

Last address

fd00::fff8:ffff:ffff:ffff

Total addresses

281474976710656

Total addresses (human readable)

2^48 addresses (281,474,976,710,656; about 281.47 trillion)

How this range is calculated

  1. 1The /80 prefix keeps the first 80 network bits fixed.
  2. 2Setting all 48 host bits to zero produces fd00::fff8:0:0:0.
  3. 3Setting those host bits to one produces fd00::fff8: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

fd00:0000:0000:0000:fff8:0000:0000:0000

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