Senderbase is offbase, need some help

Jon Lewis jlewis at
Sat Apr 17 18:07:04 CDT 2010

On Sat, 17 Apr 2010, William Herrin wrote:

> On Fri, Apr 16, 2010 at 6:25 PM, Mike <mike-nanog at> wrote:
>>   I've tried to get the attention of senderbase, which is claiming activity
>> from my address space which is in fact either un-routed or within dynamic
>> subscriber blocks that have outbound smtp filtering in effect.
> Interesting; I see similar results for my address space. Two
> addresses, one of which hasn't been attached to a machine for a decade
> and the other a virtual IP on a web server where the particular IP
> never emits connections. Magnitude's only "0.48" for both but still,
> they shouldn't even appear.

I suspect a bug in their system.  I checked a handful of unrouted blocks 
from our address space and eventually hit a /24 from which senderbase 
lists an IP with magnitude 0.48, but the space hasn't been routed for 13 
months.  They say they saw something from it on 2010-04-06...which I'd say 
is highly unlikely.

  Jon Lewis                   |  I route
  Senior Network Engineer     |  therefore you are
  Atlantic Net                |
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