[SURBL-Discuss] ccTLDs and multiple queries

John Fawcett johnml at michaweb.net
Wed Apr 21 22:21:16 CEST 2004


----- Original Message ----- 
From: "Eric Kolve"
> Initially, when I released spamcopuri I decided to pretty much ignore
> whether the TLD was a country code or not.  This results in about
> twice as many queries as necessary, but guaranteed you would get
> hits if the domain was listed.
>
> Now that people are pointing this to other RBL's beside just surbl,
> should we continue to do second and third level queries? Or just
> the query that we assume to be necessary?  My concern is that not
> all RBLs will process the domains according to a list such as
> http://www.bestregistrar.com/help/ccTLD.htm.  I suppose the worst
> case scenario is we end up getting a miss when we should be getting
> a hit because one side presumes that say TLD .za has a subdomain 'foo',
> when the server doesn't.  The server side would expect a second level,
while
> the client would do a third level query (this is why I wanted the wildcard
> records).  I guess this really isn't that great a consequence considering
> the savings and the fact that this shouldn't occur very often.
>
> I will go ahead and make this change if everyone is comfortable with the
> known risk.
>
I think if an rhsbl is listing a second level registry domain
(like .co.uk) then I think it's up to the list maintainer to implement
the wild card so that xxxxx.co.uk returns an A record. I wouldn't
worry about taking into account such an extreme case,
since I cannot imagine any list wanting to do such widespread
blocking.

I believe there should be a mechanism which distinguishes whether
a second or third level lookup is required based on a static
lists of domains known to have or not have subdomains.
If nothing is known then the default should be to check both
second and third as at present.

John



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