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IPv6 /82 Subnet Calculator

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A /82 leaves 46 host bits (2⁴⁶ addresses). It is smaller than a /64 LAN and appears in specialized schemes — for example /96 embeds a 32-bit IPv4 address for NAT64 or IPv4-mapped addressing.

/0
/128

/82 = 2⁴⁶ addresses (≈ 7.04 × 10¹³)

Results for 2001:db8:abcd:12::/82

Documentation (RFC 3849)Global scope
Network / prefixThe first address — identifies the subnet itself
First addressSubnet-router anycast; first address in the block
Last addressThe highest address in this block
Prefix maskEquivalent to /82
Total addresses≈ 7.04 × 10¹³ addresses
Address typeGlobally routable scope
More detailsNeighboring subnets, expanded address, reverse DNS, and hextet breakdown

Neighboring /82 subnets

Expanded address
Compressed address
Network (expanded)
Last address (expanded)
Prefix mask
Total addresses (exact)
Reverse DNS (PTR)
Host bits / network bits

Hextet breakdown

20010db8abcd00120000000000000001
NetworkSplit groupHost

Quick facts for IPv6 /82

IPv6 /82 reference guideBit split, overview, key facts, sizing tables, design notes, standards, and FAQ

Network / host bit split

Network bits (82)Split hextetHost bits (46)
Network bits
82
Host bits
46
Prefix mask
ffff:ffff:ffff:ffff:ffff:c000::
Total addresses
2⁴⁶
Approx. count
7.04 × 10¹³
/64 subnets
Addresses formula
2^46
/64 relationship
smaller than a /64

Overview

A /82 leaves 46 host bits (2⁴⁶ addresses). It is smaller than a /64 LAN and appears in specialized schemes — for example /96 embeds a 32-bit IPv4 address for NAT64 or IPv4-mapped addressing.

Common use cases

  • NAT64 and IPv4-embedded addressing study
  • Specialized translation gateway design
  • Protocol documentation and examples

Key facts

  • A /82 fixes 82 network bits and leaves 46 host bits — 2⁴⁶ total addresses.
  • In network design terms, /82 is typically a specialized sub-/64 block.
  • A /82 is 1/2¹⁸ of a standard /64 LAN subnet.

Design guidance

A /82 is a specialized size, not a general LAN substitute. Production VLANs should remain /64. Use /82 only when a protocol or design explicitly calls for it — for example /96 in NAT64 translation — or in controlled lab environments.

Practical example

In a lab, 2001:db8:abcd:0012::1/82 might number a small segment with 2⁴⁶ addresses. In production, you would normally expand this to a full /64 unless you have a documented exception.

Prefix sizing reference

Divide /82 into…

PrefixSubnetsAddresses each
/8322⁴⁵
/8442⁴⁴
/86162⁴²
/902562³⁸

/82 fits inside…

SupernetAddresses/82s inside
/812⁴⁷2
/802⁴⁸4
/782⁵⁰16
/742⁵⁴256

Frequently asked questions

Common questions about IPv6 /82 blocks, prefix sizes, and use cases.