[lir-wg] AS Number Policy

Several examples:

1. Confederate AS : only the top level AS number is announced by design, all
member ASes should not be visible outside the confederate.
2. CIDR aggregate : If customer's address got aggregated by upstream ISP,
usually you won't see their AS numbers from the upstream ISP's CIDR
(especially for those people like to filter on allocation boundary). 

Technically I don't see how RIPE NCC can possibly find all the ASes that are
originated but invisible to the public route server.

Ping Lu
Cable & Wireless USA
Network Tools and Analysis Group
W: +1-703-292-2359
E: plu at cw.net


> -----Original Message-----
> From: Vladimir A. Jakovenko [mailto:vovik at lucky.net]
> Sent: Tuesday, July 09, 2002 3:26 PM
> To: Lu, Ping
> Cc: 'wtremmel at vianetworks.com'; 'Matthew Robinson'; Wilfried 
> Woeber, UniVie/ACOnet; lir-wg at ripe.net
> Subject: Re: [lir-wg] AS Number Policy
> 
> 
> On Tue, Jul 09, 2002 at 02:01:26PM -0400, Lu, Ping wrote:
> >This has nothing to do with the private AS-number.
> >
> >If an AS number existed in our backbone (public to CW) but not to
> >RIPE NCC's route server. Will that be considered NOT USED ?
> 
> Could you possibly provide us with more examples in which 
> circumstances someone 
> may need to use AS number from the PUBLIC range instead of 
> using AS number from 
> PRIVATE range in the case when there is no need to advertise 
> any prefixes 
> originated by such AS-number to the PUBLIC Internet (i.e. 
> this AS number will 
> never be visible outside of some private network)?
> 
> I can remind only one case - some kind of IX, are used by 
> some ASes to 
> exchange routing information localy. Generaly speaking IX-AS 
> may not be 
> visible from PUBLIC, but in the most cases, especialy if we 
> are talking 
> about enterprise networks, same results may be achieved by 
> using AS-number 
> from private range.
> 
> By way of proof - AS15645 is used for the public Ukrainian 
> Internet-Exchange.
> Appearance of any prefixes originated by this AS outside of 
> IX members networks
> violates IX rules and should be avoided. 
> 
> Lets summarise - there ARE circumstances when AS number from 
> PUBLIC range may 
> be requested and used being invisible from the majority of 
> the Internet. 
> 
> It would be nice to mention that in policy and provide some examples.
> 
> -- 
> Regards,
> Vladimir.
>