Re: The same prefix originated within two different ASs

[Vadim Antonov <[e-mail]>]

>Can someone please reiterate to me, from experience, reasons why a prefix
>shouldn't be advertised as originating from two separate ASs?

Because it breaks underlying assumption after AS-path based policies that
all prefixes are split into groups by originating AS-es.  I.e. if you
do that somebody's preferences or filters based on originating AS-es
may behave incoherently, potentially creating persistent routing loops.

Since nobody has the complete knowledge of Internet policies breaking
that assumption is not safe.  Who knows what lurks in the dark places.

--vadim