It might be policy, but I don't believe it to be practice. I have no problem reaching Verio from our /20 block. Oddly enough Verio (AS 2914) is advertising several /20 netblocks out of 206/8. Even more specific they are advertising as small as a /23 from 206/8. Further, they provide transit for customers advertising /24s. It might be possible that someone at Verio is not applying their policy, if one does indeed exist. Anyone from Verio care to comment? On Thu, 17 Jun 1999, Mark Cobb wrote:

I believe that some agencies, such as Verio and Expedia are filtering out anything longer than /19. In fact, I know that Verio is and they said that they would not change this policy. ARIN changed the policy, but RIPE and APNIC have not; this is their excuse for not changing their policies.

"Michael P. Lucking" wrote:

...

In February we received a new /20 CIDR from ARIN. I felt that we might be caught by the filters at ISPs like Sprint (http://www.sprint.net/filter.htm). I contacted Sprint twice and spoke to two different engineers, both told me that they were not filtering as their page described, and they would allow advertisements for /20 in 206/8 - 233/8. Since that time I have spoken to several people who purchase transit from Sprint, and they do indeed see my advertisements. Looking at NetFlow stats I can't find any major provider that we have not had traffic flow between. I assume they had to have accepted my advertisements, nobody runs BGP and default routes :).

BTW: I also contacted, and received a similar response from ANS.

========================================================================= Michael P. Lucking Michael@Lucking.COM