Re: Detecting and disabling bad DNSBLs

[Steve Linford <[e-mail]>]

The standard is to query the DNSBL's Loopback address, 127.0.0.2. If  
the Loopback address does not respond the DNSBL is either shutting  
down or it's defunct. You query the Loopback address like this (using  
our SBL as an example) and should get this answer:

;; QUERY:
;2.0.0.127.sbl.spamhaus.org.

;; ANSWER:
2.0.0.127.sbl.spamhaus.org. 900  IN A   127.0.0.2
2.0.0.127.sbl.spamhaus.org. 1800 IN TXT	
      "http://www.spamhaus.org/SBL/sbl.lasso?query=SBL233"

(if you get no answer to a 2.0.0.127.dnsbl query, the no answer means  
"it's dead Jim" or possibly "it's firewalling you Jim")

Chris Lewis's excellent DNSBL BCP document also covers how to shut a  
DNSBL down properly.

Regards,

   Steve Linford
   The Spamhaus Project
   http://www.spamhaus.org


On 15 Nov 2008, at 09:41, Peter Dambier wrote:

> Maybe I am a bit late with this idea.
>
> I remeber dns roots switching off and DNSBLs switching off.
>
> Users wont notice until broken - or not even then.
>
> The sysop has been fired.
>
>
> There should be a means for the DNSBL to tell its client
>
> 1) I am not a DNS-server
>
> 2) I am going to switch off soon
>
> 3) There should be a serialnumber or timestamp on the DNSBL
>    to show when it has last been maintained.
>
>
> When the client sees the wrong type of server it should
> warn both the sysop and the user. Today it has no means
> to decide so.
>
> Kind regards
> Peter
>
> -- 
> Peter and Karin Dambier
> Cesidian Root - Radice Cesidiana
> Rimbacher Strasse 16
> D-69509 Moerlenbach-Bonsweiher
> [phone] (Telekom)
> [phone] (VoIP: sipgate.de)
> mail: [e-mail]
> http://www.peter-dambier.de/
> http://iason.site.voila.fr/
> https://sourceforge.net/projects/iason/
> _______________________________________________
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