[rbldnsd] AAAA Queries?

[Victor Duchovni]

On Fri, Jul 28, 2006 at 09:42:26AM -0400, Bri Bruns wrote:

> Here's whats going on, and its very simple.  On machines with IPv6 
> enabled and functioning, for example, a Linux box, the resolver queries 
> go by default AAAA lookup, then a normal A lookup.  I can't remember 
> why - I think it has something to do with an IPv6 related RFC, where 
> IPv6 is supposed to be tried first before IPv4 unless the resolver 
> library is explicitly told to do so otherwise.

True for getaddrinfo(), but RBL lookups are not usually made from the
C-library getaddrinfo() routine. Rather RBL aware software makes
explicit DNS "T_A" lookups. If somebody writes broken RBL lookup
software that uses getaddrinfo() they need to be sent off for
"re-education"...

> Since all of my servers and dns servers are IPv6 enabled, this is what 
> happens.  Currently, we can even accept AHBL dnsbl queries directed at 
> one of the servers via IPv6 as well (the others either I dont have 
> control over, or haven't had time to set it up).

This is not a good explanation. The issue is a badly written RBL
lookup client. Postfix for example, will not make "AAAA" RBL lookups
even on the platforms you describe.

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