How to compute db.192.168.x names from network addresses ?

Matus UHLAR - fantomas uhlar at
Thu Oct 1 16:13:28 UTC 2020

On 01.10.20 17:46, Olivier wrote:
>Here or there, you can read configuration files named like db.192.168.42
>when holding data for a network.
>For networks with a /24 mask, simply striping  ending 0/24 substring from
> is enough.
>But what about network with a different prefix ?

2317 Classless IN-ADDR.ARPA delegation. H. Eidnes, G. de Groot, P. Vixie.
     March 1998. (Format: TXT=17744 bytes) (Also BCP0020) (Status: BEST
     CURRENT PRACTICE) (DOI: 10.17487/RFC2317)

>1. How can you compute this "db.192.168.whatever" from 192.168.x.y/z
>network address ?

better set up reverse zones 192.168.0, 192.168.1 etc.
the RFC above should be only used for  <24 ranges.

>Example in Python would be appreciated.
>2. Instead of using short "db.192.168.42" names, I used a long
>"db.". I didn't notice any issue. Did I overlooked something ?

it's just a file name.  You can use "myrevzone" as long, but using
db.192.168.42 is much more explanatory.

Matus UHLAR - fantomas, uhlar at ;
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Varovanie: na tuto adresu chcem NEDOSTAVAT akukolvek reklamnu postu.
Windows 2000: 640 MB ought to be enough for anybody

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