Re: [Asrg] rDNS

[Alessandro Vesely <[e-mail]>]

der Mouse wrote:
>> There are different geographic regions and organizations that refuse
>> to publish reverse DNS.
> 
> This is true.  In my experience being one of them correlates
> positively, and at least moderately strongly (though of course not
> perfectly), with being part of the precipitate.

(as opposed to being part of the "solution", I guess)

Possibly, this scarceness corroborates the belief that rDNS results 
are more trustworthy than direct DNS records.

>> As an anti-abuse effort, some providers [...] do not
>> accept connections without a reverse DNS entry being found.

This used to be typical of FTP servers in the '80s. However, some 
feedback loop providers apparently make use of it today. Let alone 
investigations about the PTR target being automatically generated or 
containing the "dynamic" keyword. IMHO, synthesizing informations on 
that basis is symptomatic of technologies in their infancy being 
desperately greedy for data they cannot obtain [otherwise].

>> As a result, these providers may be unable to communicate with some
>> organizations or geographic regions.
> 
> Right.  So?  Someone who doesn't tolerate dashes in domain names won't
> be able to communicate with rodents-montreal.org, either.

I never heard about dash-intolerants. Are you kidding?

>> Who is wrong, because in the case of email, reverse DNS is clearly
>> being misused.
> 
> It's not clear to me that anyone is wrong there, nor that rDNS is being
> misused.

Much like whois, rDNS is being used in relation with the possibility 
to individuate who, if any, is responsible for running a host at the 
given address. DNSBLs, certificates, reputation, etcetera, all rotate 
around allocations of those IP numbers, but rDNS dependence reveals 
unreadiness for a truly virtual environment: What if _all_ IPs were 
dynamic?