[dns-operations] NXDOMAIN rewriting by lying resolvers (Was: new public DNS service: 9.9.9.9

[wbrown at e1b.org]

"Stephane Bortzmeyer" <bortzmeyer at nic.fr> wrote on 11/21/2017 11:14:17 AM:

> > a better test is to query for a totally bogus domain, and see what
> > you get back.  Google will return NXDOMAIN, an ISP will usually take
> > you to a search page or the like.
> 
> "Not all ISPs" (yes, this is a reference to recent political campaigns)

I did not intend to imply all ISPs do this.  But if they do, this is 
probably the most reliable test as it will discover IP address hijacking 
as well as redirecting port 53 and detecting NXDOMAIN and offering 
"suggestions".



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