Re: [exim] hostslist IP matching and *.example.com

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Author: Marc Sherman
Date:  
To: exim-users
Subject: Re: [exim] hostslist IP matching and *.example.com
WJCarpenter wrote:
> I think I used to know the answer to this, but I was just looking at
> section 10 of the exim spec and didn't find the info I was looking
> for. (Treatment of various other things is laid out pretty well, but
> not this case.)
>
> If you have a wildcard host name item in a hostlist that needs to
> match by IP, is there any forward-DNS checking against the results of
> the reverse DNS lookup?


Yes. Pretty much anywhere that the exim spec says "reverse DNS lookup",
it actually means "forward verified reverse DNS lookup". This isn't very
well documented, last time I looked; I think the idea is that it's so
obvious that the one-step reverse check is spoofable, that the forward
verification step is assumed.

- Marc