Re: filtering /48 is going to be necessary

On 09.03.2012 20:31, Owen DeLong wrote: Hi,

Let us not forget that there is also the issue of PA /48s being advertised (quasi-legitimately) for some end-user organizations that are multi-homed but choose not to get PI space. It is not uncommon to obtain a PA /48 from provider A and also advertise it from Provider B.

While I agree it's not uncommon, I'm not a big fan of this setup. Also, provider A should still have his aggregate announced, which would allow strictly filtering ISPs to reach the destination anyway. Announcing /48s from a PA block without the covering aggregate calls for trouble. Bernhard