rndname.dnsp.co
The caching test, in alias form.
What it does
The same idea as random, expressed as a randomised CNAME. Useful where the tool you are testing follows aliases but never shows you the final address.
Example
$ dig @dnsp.co rndname.dnsp.co CNAME +short
r8f2ka.rndname.dnsp.co.
Reading the answer
a different alias each time
Nothing cached the record.
a repeated alias
A cache answered.
Notes
- Some clients silently follow the alias. Ask for the CNAME record explicitly.