Re: So -- what did happen to Panix?

[bmanning () vacation karoshi com]

On Fri, Jan 27, 2006 at 11:39:27AM -0500, Joe Abley wrote:
> On 27-Jan-2006, at 11:12, bmanning () vacation karoshi com wrote:
>
> >     but by definition, the right-most entry is the prefix origin...
>
> Suppose AS 9327 decides to originate 198.32.6.0/24, but prepends 4555  
> to the AS_PATH as it does so. Suppose 9327's uses a transit provider  
> which builds prefix filters from the IRR, and the "as9327" aut-num  
> object is modified to include policy which suggests 9327 provides  
> transit for 4555. Suppose this is not actually the case, though, and  
> in fact 9327 is a rogue AS which is trying to capture 4555's traffic.
>
> The rest of the world sees a prefix with an AS_PATH attribute which  
> ends with "9327 4555".
>
> In this case, from the point of view of those trying to discern  
> legitimacy of advertisements, what is the origin of the prefix? Is it  
> 4555, or 9327?


        from BGP's perspective, you tell me.  being the naive BGP
        listen/speaker - i think that AS 4555 is the origin.

        now... what does  Prefix 198.32.6.0/24 say is the correct
        origin?  

> Is it possible to tell, from just the right-most entry in the AS_PATH  
> attribute?

        nope - but you have jumped right into the path question.
        (what does the as4555 aut-num object say about using 9327
        as an upstream AS?)

        
> Joe
>
> [note: 9327 is not a rogue AS, in fact. This is just hypothetical :-)]

        sez you :) (reminder to send Cingular the royalty check if you
        receive the above two characters ":" and ")" as listed above
        AND you chose to infer mood or intent.)

        I think -all- AS are run by rouges and pirates.

-- (headless) bill