The block message is 521 DNSRBL: Blocked for abuse

John Curran jcurran at
Tue Sep 24 11:58:22 UTC 2013

On Sep 18, 2013, at 10:46 PM, Mark Andrews <marka at> wrote:

> Which is irrelevent to removing a address block on the basis of a
> RIR recording that the block has been reallocated.  A reallocation
> already goes through a quarantine period though that may get shorter
> as time goes on.
> A transfer on the other hand doesn't.

Correct.  A transfer is not an issuance of space, and could very easily 
be to a recipient related to the original party that caused the current 

Whereas the issuance of address space to a qualified requestor (even if 
previously issued and now returned to ARIN) is far more likely to an 
unrelated new party than anyone related to the original block holder.  

> There may be some use in recording whether a address block is
> transfered or allocated.  Note I'm not sure if the allocation
> date gets updated on a transfer or not.

The arin-issued feed is simply issued resources (not transfers) - 

It is highly recommended that folks running reputation systems monitor
this feed and avoid penalizing parties being issued resources, as those
requesting have no control over the prior history of these blocks before
their return to ARIN.

We are going to see quite a bit more of reissued blocks as we get down
towards the bottom of the available pool in this region (i.e. over the
next 6 to 12 months)


John Curran
President and CEO

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