>Well, without naming names, the prefix-length based filtering is
>done on non-customer routes. A byproduct of this is it grudgingly
Well, yes, but now that multiple providers are doing this the fact that
they are non-customer filters affects anyone who is not a customer of BOTH
providers, thus further encouraging people to aggregate. I would not mind
seeing these filters become more prevalent, making it unreasonable for
people to become customers of everyone who filters to get around the
filters. Renumbering is NOT that hard folks, and it DOES help.
Erol's Internet Services
ISP/C Director at Large
Renumbering is not that hard IF you are an end-user and it only affects one
or two links (ie: a /24 or two).
It is atrociously difficult if you're an ISP and have sold sizeable
connections to end-users, some of them with significant installed base
(ie: a school system with a dozen buildings across a metro area and a
thousand or more systems, along with the infrastructure to interconnect
It also will disrupt service if you're serving web pages or doing other
things that require stable IP numbers.
In general I agree that renumbering in the general case for end customers
isn't that big a deal. However, for ISPs there are significant legal and
operational issues raised by being forced to renumber due to a change in
Actions which operational groups such as NANOG take that cause those
hardships are, in my opinion, dangerous on a business level.