Expand Documentation Address 2001:db8::1

Expand the IPv6 documentation address 2001:db8::1 to its full form. Learn about RFC 3849 and why 2001:db8::/32 is reserved for examples.

Special Addresses

Detailed Explanation

The Documentation Prefix 2001:db8::/32

The address 2001:db8::1 expands to:

2001:0db8:0000:0000:0000:0000:0000:0001

Why This Prefix Exists

RFC 3849 reserves the 2001:db8::/32 prefix exclusively for use in documentation, examples, and sample code. This ensures that:

  • Example addresses never conflict with real addresses on the Internet
  • Documentation code can be safely copied without accidentally connecting to unintended hosts
  • Network diagrams and tutorials use a universally recognized non-routable prefix

Equivalent in IPv4

IPv4 has similar documentation ranges defined in RFC 5737:

IPv4 Range IPv6 Equivalent
192.0.2.0/24 2001:db8::/32
198.51.100.0/24 (same)
203.0.113.0/24 (same)

Common Usage Patterns

2001:db8::1          # Simple example host
2001:db8:1::/48      # Example site prefix
2001:db8:abcd::1     # Example with readable prefix
2001:db8:cafe::/48   # Memorable example prefix

Routing Behavior

Addresses in 2001:db8::/32 should never appear in routing tables on the public Internet. If they do, it indicates a misconfiguration.

Use Case

Used in technical documentation, RFCs, tutorials, blog posts, training materials, and network diagrams. Any time you need to show an example IPv6 address in documentation, use the 2001:db8::/32 prefix to avoid accidentally referencing real addresses.

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