Re: [Idr] new ID on expansion of private use ASN range

[Jon Mitchell <[e-mail]>]

James - all of these operational concerns exist today with the existing
private Use ASN range when it meets the Internet, and this document is
just acknowledging what operators are already doing (making use of
vendor specific knobs).  Text that generally states private Use ASNs
should not be advertised to the Internet is also in RFC 1930 - section
10.

This document does not intend to dictate as much as acknowledge
operators are using these knobs and providing some general guidance that
they make sure such vendor implementations are updated in accordance
with the draft if they are using them to remove private use ASNs towards
the Internet before using the new range (providing transition guidance
for when/if it's first published).  In my experience, the L3VPN
providers tend towards knobs like allow-as-in and as-override rather
than remove-private so the statements would not be applicable as they
don't rely on features that recognize private use ASNs, but in any case
this document was not intended to define any features or changes to
protocol behavior.  As far as I've read (which is by no means every RFC)
none of these vendor knobs that do AS_PATH manipulation are documented
through the IETF process.

As far as impact, there are are a number of private Use ASNs advertised
to the Internet at any given time with no large (Internet wide) impact,
but presumably there may be some small impact if a route with one of
these ASNs was received by an ASN w/o an inbound AS_PATH filter to block
them which was using such ASN internally to it's network and was
therefore dropped.  So the impact is limited mostly to connectivity to
those who do no correctly remove the private ASNs.

Jon

On Tue, Jul 03, 2012 at 01:44:42AM +0000, UTTARO, JAMES wrote:
> Jon,
> 
> 	Seems reasonable.. I do not fully get the context.. You describe the fact that the increase in the number of AS across both l3VPN and Internet use cases are expanding rapidly.. No Doubt... So I see the creation of the new spaces and ranges.. My concerns are in re the Operations Considerations Section
> 
> a) You are creating a set of rules for the internet routing context.
> 
> "  If private use ASNs are used and prefixes are originated from these
>    private use ASNs which are destined to the Internet, private use ASNs
>    must be removed from the AS_PATH before being advertised to the
>    global Internet.
> "
> How does this effect folks who use AS_PATH and/or AS_CONTENT in routing policy decisions? Better question is there an issue if all of the Private ASNs are stripped?
> 
> b) You specify no rules in re the L3VPN routing context(s). 
> 
> c) Not sure how this would work? If someone screws up what is the collateral damage?
> 
> "  Prior to making use of the second, numerically
>    higher, range of these ASNs network operators should be confident any
>    implementation specific features or filters that recognize private
>    use ASNs have been updated to recognize both ranges correctly so that
>    no unintended announcement of private use ASNs to the Internet
> "
> 
> Thanks,
> 	Jim Uttaro
> 
> 
> -----Original Message-----
> From: [e-mail] [mailto:[e-mail]] On Behalf Of Jon Mitchell
> Sent: Monday, July 02, 2012 12:49 PM
> To: [e-mail]
> Subject: [Idr] new ID on expansion of private use ASN range
> 
> 
> IDR WG folks -
> 
> I hope you can take some time from the normal debate(s) to consider and
> review a fresh draft on expanding the ASN space reserved for Private
> Use.  All comments regarding content, clarity or structure welcome.
> 
> Cheers,
> 
> Jon
> 
> --
> 
> A new version of I-D, draft-mitchell-idr-as-private-reservation-00.txt
> has been successfully submitted by Jon Mitchell and posted to the IETF
> repository.
> 
> Filename:        draft-mitchell-idr-as-private-reservation
> Revision:        00
> Title:           Autonomous System (AS) Reservation for Private Use
> Creation date:   2012-06-20
> WG ID:           Individual Submission
> Number of pages: 4
> URL:
> http://www.ietf.org/internet-drafts/draft-mitchell-idr-as-private-reservation-00.txt
> Status:
> http://datatracker.ietf.org/doc/draft-mitchell-idr-as-private-reservation
> Htmlized:
> http://tools.ietf.org/html/draft-mitchell-idr-as-private-reservation-00
> 
> 
> Abstract:
>    This document describes the reservation of Autonomous System numbers
>    (ASNs) that may be used within networks but should not be advertised
>    to the Internet, known as private use ASNs.  This document enlarges
>    the total space available for private use ASNs by documenting the
>    reservation of a second larger range and updates RFC 1930.
> 
>                                                                                   
> 
> 
> The IETF Secretariat
> 
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