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Calcrivo

IPv6 Hex Converter

Turn an IPv6 address into a bare 32-digit hex string, 0x literal and reverse-DNS nibble format.

Inputs

32-digit Hex

20010db8000000000000000000000001

0x Literal

0x20010db8000000000000000000000001

Reverse DNS (ip6.arpa)

1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa

Hex Digits

32

Step by step

  1. Values used

    IPv6 address = 2001:db8::1

  2. IPv6 Hex

    The eight groups are concatenated into 32 hex digits; reversing the digits and joining them with dots gives the ip6.arpa name.

  3. 32-digit Hex

    = 20010db8000000000000000000000001

  4. 0x Literal

    = 0x20010db8000000000000000000000001

  5. Reverse DNS (ip6.arpa)

    = 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa

  6. Hex Digits

    = 32

How it works

A flat hex string is the form used by databases, TCAM entries and log pipelines. Reverse DNS uses the same digits in reverse order, one nibble per label. PTR records for IPv6 are painful to build by hand, and a single transposed nibble makes reverse lookups fail in ways that are hard to spot.

Formula

IPv6 Hex

The eight groups are concatenated into 32 hex digits; reversing the digits and joining them with dots gives the ip6.arpa name.

ip6.arpa
Reverse DNS zone for IPv6, one label per hex nibble

Frequently Asked Questions

How is IPv6 Hex calculated?

The eight groups are concatenated into 32 hex digits; reversing the digits and joining them with dots gives the ip6.arpa name. A flat hex string is the form used by databases, TCAM entries and log pipelines. Reverse DNS uses the same digits in reverse order, one nibble per label.

Why does IPv6 Hex matter?

PTR records for IPv6 are painful to build by hand, and a single transposed nibble makes reverse lookups fail in ways that are hard to spot.

What values do I need to enter?

This calculator takes 1 input: IPv6 address. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.

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