[rbldnsd] multiple TXT element answers?

[Kai Schlichting]

[repost to list of what was private mail to me prior, my answers are in-line]

On Wed 05/17/06 at 12:42 AM, "Amos Jeffries" <amos at treenetnz.com> wrote:

> ----- Original Message ----- 
> From: "Kai Schlichting" <kai-rbldnsd-list at spamshield.org>
> To: <rbldnsd at corpit.ru>
> Sent: Wednesday, May 17, 2006 2:05 PM
> Subject: [rbldnsd] multiple TXT element answers?


>> Greetings everyone - I recently joined the list.
>>

> Greetings.

> It sounds like you would be much better suited to running bind as a mirror
> and accepting the zone in the format they provide.

and my idea is to make it work better and more efficiently - possibly for
them (routeviews.org), too.

> However as an interesting problem I'll go on to show how its done.

> <snip examples>
>> relevant entries for the example above:
>>
>> 55.5.12         IN TXT  "12163" "12.5.48.0" "21"
>> *.55.5.12       IN TXT  "12163" "12.5.48.0" "21"
>> 55.5.12          IN TXT  "12163" "12.5.54.0" "23"
>> *.55.5.12       IN TXT  "12163" "12.5.54.0" "23"
>>
>> My attempts to replicate this return of multiple TXT elements in quotes
>> with rbldnsd have
>> failed so far.
>>
>> rbldnsd version 0.996 (19 Feb 2006)
>>
>> I've tried an ordinary ip4set datatype (requiring a rewrite of the above
>> data's left side),
>> as well as a dnset datatype where one can more or less take the above data
>> into the zone
>> directly.
>>
>> Problem: no matter how I try to define the TXT record, the result is
>> always an entire quoted
>>         string, quotation-marks are escaped with backslashes:
>>

> The zone format by design is built to return one reason per TXT record; not
> split them up like that.
> However, rbldnsd can provide multiple TXT results for any IP lookup.

these would be separate records returned , and that's not how routeviews.org
people designed it - as we know by way of Michael's follow-up to the list by
now: a single response can have multiple TXT chunks - which is what BIND
returns if it has multiple quoted strings in a TXT record.


> The way to supply multiple TXT records for a lookup is to create one line
> for each TXT.
> Zone File:
>     12.5.54.0/23    12163
>     12.5.54.0/23    12.5.54.0
>     12.5.54.0/23    23
>     12.5.48.0/21    12163
>     12.5.48.0/21    12.5.48.0
>     12.5.48.0/21    21

Produce>> host -t TXT 1.55.5.12.test  localhost

>     1.55.5.12.test descriptive text "12163"
>     1.55.5.12.test descriptive text "12.5.54.0"
>     1.55.5.12.test descriptive text "23"
>     1.55.5.12.test descriptive text "12.5.48.0"
>     1.55.5.12.test descriptive text "21"

> This creates a nasty expansion of the zone file size and possibly of the
> rbldnsd memory footprint.

> Is there any real reason the TXT have to be multiple?

same answer as above: routeviews.org made it this way, and users of this
DNS-service expect it this way: can't change format at this particular
moment.

> The countries and ASN RBLS have a nicer output format for things like this,
> where the core ASN/country is encoded in the A result and further details
> strung in the TXT.

> AYJ

I am aware of blackholes.us - what other country/ASN DNSBL's are you referring to?

Thanks,
bye,Kai