NSPs and filters

randy@psg.com (Randy Bush) wrote:

So, at POP X, I take in maybe 100 prefixes, with maybe 1000 at some POPs.
How do I build and maintain that filter list, and how long does it take each
packet to get through it with a router that also does real routing?

That can be done, and is relatively easy. Not in cisco's or any other
hardware-assisted box, though (figuring out why is left as an
excercise to the reader :slight_smile:

My estimate is that the total filtering overhead is at about 2.5% for
a "software" router. And, yes, i do plan to implement that kind of


PS. Hint: i described the technique for doing that in a mailing
    list, year ago.