dotted AS numbers in asn.txt

Henk Uijterwaal henk at
Thu Sep 20 06:02:25 UTC 2007

Joe Abley wrote:

> On 19-Sep-2007, at 1417, Andreas Ott wrote:
>> since when does contain dotted
>> AS numbers?

When I prepared my talk for the February NANOG meeting, there were
3 of them in the file.  This must have happened between 1/1 and
late January.  (1/1 being the day they started handing out ASN32's).

> Good question, for the reason you noted below (breaking scripts). If I 
> was to guess I'd say it happened shortly after ARIN assigned their first 
> 32-bit AS number.
>> Where is the new formatting documented, asn.h ?
> contains pertinent words, but I imagine it's not strictly accurate to 
> call that documentation for ARIN's presentation format decisions 
> (although maybe it is, to all intents and purposes, since I seem to 
> think that George's draft mainly seeks to document practice that the 
> RIRs have already agreed on, between themselves).

The draft Enke Chen draft/RFC proposing to extend the ASN space to 32
bits says nothing about the format.  The first idea was to use X:Y,
but this lead to confusion with community strings.  X.Y didn't so this
was informally used.

Early 2006, proposals in all 5 regions asking the RIRs to start handing
out ASN32 as of 1/1/2007.  When implementation work started (summer
of 2006), this document was submitted to describe the current practice.
As this was the only document describing the format, this is what the
RIRs started to use.


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