Choosing Domain Names and IPs for Documentation

When writing documentation it is a good practice to not use public/valid domain names or IP addresses. The RFC documents listed below provide domains and ips that can be used for examples or documentation purposes.

Domains

Domains reserved for documentation are described in

• RFC2606 - Reserved Top Level DNS Names
• RFC6761 - Special-Use Domain Names.

Top level domain names reserved for documentation:

• .test for testing
• .example for examples
• .invalid obviously for invalid domain names
• .localhost only pointing to the loop back IP address

Second level domain names reserved for documentation:

• example.com
• example.net
• example.org

IPv4

IPv4 addresses reserved for documentation are described in

• RFC1918 - Address Allocation for Private Internets
• RFC6598 - IANA-Reserved IPv4 Prefix for Shared Address Space
• RFC6890 - Special-Purpose IP Address Registries
• RFC8190 - Updates to the Special-Purpose IP Address Registries

and obsolete

• RFC3330 - Special-Use IPv4 Addresses
• RFC5735 - Special Use IPv4 Addresses

IPv4 documentation only network block is

• 192.0.2.0/24

Address space:

• 10.0.0.0 - 10.255.255.255 (10/8 prefix)
• 172.16.0.0 - 172.31.255.255 (172.16/12 prefix)
• 192.168.0.0 - 192.168.255.255 (192.168/16 prefix)

IPv6

IPv6 addresses reserved for documentation are described in

• RFC3849 - IPv6 Address Prefix Reserved for Documentation.

IPv4 documentation only network block is

• 2001:DB8::/32