Pelle WessmanJun 21, 2023

Reminder that the only safe dummy domains to use are:

- example.com
- example.net
- example.org

And nowadays there's also a safe dummy TLD: .example

These are safe because they are reserved by IANA as as special-use domain names for documentation purposes on direction of IETF in RFC 2606 and RFC 6761.

Any other domain can be registered and as such should _never_ be used as a dummy domain for documentation or as eg. an example in default configs.

See: https://en.wikipedia.org/wiki/Example.com

example.com - Wikipedia

Show threadMichael DexterJun 22, 2023
@voxpelli
Haven't the NFT ones all freed up?
@encthenet
Show threadJohn-Mark GurneyJun 22, 2023

@dexter
Just because they are unused today doesn't mean they won't be reused again tomorrow.

There is also the equivalent for IP addresses as well.

@voxpelli

Show threadMichael W Lucas Jun 22, 2023

@encthenet @dexter @voxpelli

When I need multiple domains for a book, I register them. Readers have trouble internalizing setups using example.net vs example.org, but two wildly different domains stand out.

(Really, I pick some of my domains that don't have the service I'm writing about and that feel right, but the point is: they are registered.)

Show threadJim P.Jun 22, 2023
@mwl @encthenet @dexter @voxpelli I also feel like using only example.<blah> domains can get confusing. Depending on the context in docs I sometimes also use "<something>.home.arpa" (RFC 8375) or "<something>.test" (RFC 6761). Now that people are more comfortable with alternate TLDs, the .test reserved TLD examples don't look as strange as they used to.
Show threadKeith WansbroughJun 23, 2023
@jimp @mwl @encthenet @dexter @voxpelli you can use subdomains of those too: alpha.example.com, beta.example.com.
Show threadJim P.Jun 23, 2023
@kw217 @mwl @encthenet @dexter @voxpelli subdomains are good for examples inside an example org but if you're trying to document an example setup between two unrelated entities then using subdomains (or even example.com vs .net) make it ambiguous. Whereas using exampleco.test and widgetsllc.test makes it much more clear they are distinct.
Show threadPelle Wessman
@jimp Should be exampleco.example though, the .test ones are intended to test the DNS system, not for documentation
Jun 23, 2023 at 5:55pmIvory for iOS
Show threadJim P.Jun 23, 2023
@voxpelli You are absolutely correct, but even though it's better in theory I've found using .example more awkward in practice, same with .invalid.
Show threadPelle WessmanJun 23, 2023
@jimp I myself opt for “example.com” for as many places as possible