IPv6 subnet calculator

IPv6 CIDR range for fd20:f000::/20

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 fd20:f000::/20

The prefix identifies a network with 108 host bits. Every address from the first address through the last address belongs to this range.

CIDR prefix

fd20:f000::/20

Network mask

ffff:f000::

Prefix length

/20

Host bits

108

First address

fd20:f000::

Last address

fd20:ffff:ffff:ffff:ffff:ffff:ffff:ffff

Total addresses

324518553658426726783156020576256

Total addresses (human readable)

2^108 addresses (324,518,553,658,426,726,783,156,020,576,256; about 324.51 nonillion)

How this range is calculated

  1. 1The /20 prefix keeps the first 20 network bits fixed.
  2. 2Setting all 108 host bits to zero produces fd20:f000::.
  3. 3Setting those host bits to one produces fd20:ffff:ffff: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

fd20:f000:0000:0000:0000:0000:0000:0000

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