Re: Purchasing IPv4 space - due diligence homework

[Nikolas Geyer <nik () neko id au>]

A big +1 to checking Spamhaus, specifically their DROP and EDROP lists. These two lists are what causes us most pain 
when acquiring IPv4 space as a lot of providers put auto blocking in place based on these two which can be difficult to 
get removed. 

I won’t even contemplate prefixes on either of these lists unless the seller knocks $5/IP off the purchase price 
because of the associated time and pain trying to clean it up. 

Sent from my iPhone

> On Apr 3, 2019, at 11:49 AM, Valdis Klētnieks <valdis.kletnieks () vt edu> wrote:
>
> On Wed, 03 Apr 2019 15:20:17 -0000, "Torres, Matt via NANOG" said:
>
> >  3.  Check SORBS blacklisting. It should not show up except maybe the DUHL list(?). If it does, walk away.
>
> SORBS isn't the only place to check. As an example, if Spamhaus doesn't have
> nice things to say about the block, it's time to start asking questions....
>
> http://www.anti-abuse.org/multi-rbl-check/ has a fairly good list of
> places that could give your customer a bad time (whether or not the
> listing is deserved - the point is that being listed anywhere there will
> probably mean problems that have to be cleaned up)
>
> You may all now begin the religious war over where else to check.