[arin-tech-discuss] Converting XML to .csv format

David Huberman dhuberma at arin.net
Thu Mar 15 12:17:56 EDT 2012

Hello Luke,

Glad we could help! You asked:

> So just to be clear with the example below, ARIN is the
> top level network just in the sense that it is in charge
> of administering this IP block. A subset of these IPs
> have been assigned to Comcast, and within comcast's
> network, a subset is assigned to Comcast Customer Org?

Exactly.  And in other examples, it will be ARIN -> OrgID1 -> OrgID2 where
OrgID1 is ARIN's customer (Comcast) and OrgID2 is Comcast's customer
(David & Luke Consulting Co.).  ISPs who sub-delegate IP address blocks to
their customers in ARIN's Whois will sometimes use customer org records,
and sometimes use OrgIDs for their customers.

You wrote:

> If whois says that has been allocated to ARIN
> in 2001, but Comcast doesn't register until
> 2003, does this mean that probably wasn't in
> use at least until the date it was assigned to Comcast?

It depends. 

Sometimes, ARIN assigns our customer an IP address block that has never
previously been assigned. Right now, for example, we're issuing some
blocks out of  That's a new /8, and the registrants of space
in that /8 are the very first registrants.

But ARIN also recycles space.  Folks return space to us when they're done
with it, and we re-issue it to a new customer.  Folks also go out of
business, and we revoke the space when they don't pay their bills, and we
re-issue the space to a new customer.  Sometimes we reclaim space due to
fraud being committed. That space also gets re-issed to new customers.

In the example, Comcast was not the original registrant of
The beginning of the block was first issued in December 1995 to @Home
Network, Milo Medin's cable internet company from way back in the day.
The bulk Whois data does not provide this data, however.  Bulk Whois is a
snapshot of how Whois looks on the day the data is downloaded.


David R Huberman
Principal Technical Analyst, ARIN

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