Re: AT&T/as7018 now drops invalid prefixes from peers

[Owen DeLong <owen () delong com>]

> 1/ For instance AT&T does not accept BGP UPDATES with 2914 anywhere in the AS_PATH except on the direct EBGP sessions 
> between 7018 and 2914. This means that you can craft BGP UPDATES with 2914 all you want, but 7018 won't accept them. 
> You can't inject yourself between AT&T and NTT using spoofing.

Sure, but RPKI plays no role in this. 

> 2/ Many networks give all their peering partners the same LOCAL_PREFERENCE, so you'll have to not only spoof the BGP 
> Origin ASN but also compete & win for the shortest path in order for your hijack to arrive at the intended location.

Also utterly and completely unrelated to ROAs. 

> We as industry essentially already have path validation for paths of length 1. This may not seem much, but since 
> people in this industry tend to peer directly with networks that matter to them. The majority of Internet traffic 
> flows over paths that have an AS_PATH length of 1.

I would buy this argument with length 1-3, but I’m not completely convinced of “1”. 

Owen