dnsbl's? - an informal survey

Justin Shore listuser at numbnuts.net
Sat May 31 15:35:34 UTC 2003

On Sat, 31 May 2003 jlewis at lewis.org wrote:

> On Sat, 31 May 2003, Mr. James W. Laferriere wrote:
> > > White listing comes with any blacklist. The blacklists in particular
> > > being discussed were the @dynamics, like the PDL and dynablock at
> > > easynet. Both lists quite clearly state how they build their lists and
> > > what they are designed to block (dynablock only takes out dialup, and
> > > PDL takes out all dynamic addressing).
> > 	Query ,  How is it determined that the address in question is
> > 	dynamic or not ?  Who/how/what makes that determination ?
> > 	This is the core of my concerns .
> It's usually determined via in-addr.arpa, whois data, or direct
> information from the provider.  When MAPS was freely available, I used to
> periodically email them updates on our IP space (please add these dial
> ranges, please remove these others).  I'm sure others did the same.
> AFAIK, they had at least one FTE who's job it was to maintain the DUL.

Many providers list their own dynamically assigned blocks voluntarily.  
It helps the fight against spam to an extent; plus it's good PR.

Someday I expect to either see someone create a list of known MTAs through 
which you must register it with some entity, or a list of everything that 
isn't an MTA--every statically/dynamically assigned desktop, laptop, home 
node, etc...  If that ever happens the results should be quite 

> Those large providers who stole copies of the DUL before MAPS pulled the 
> plug on them, and continued to use them without maintenance still annoy 
> me as we've run into issues multiple times with space removed from the DUL 
> still being in their private copies.

I agree.  Something like that could have large chunks go stale in a hurry.  
If you toss in the number of providers going belly-up since MAPS went
commercial, then that's a lot netblocks that shouldn't be in the DUL and
aren't if people are paying for a current copy (like we do).


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