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?