I mean that, if there is rule no allow some prefixes, all ISP should follow this
rule. All! It's the issue.
Else, we have just what we have tiday - everything work, but some stohastic
filtering add a lot of unpredicted behaviour into the routing. I know a lot of
such specifics (class B / 24, see 144.206.* for example) which (1) work OK, (2)
surely some part of the routing follow 144.206/16, but at some point /24
speciics appear and routing became just as it should be).
Today, the only 2 rules are:
(1) some blocks (195.* etc) can't use more than /20 (npot /19) specifics; it
began a few years ago due to the Sprint policy;
(2) Less than /24 announces are not mainly allowed.
If someone want more (and no doubt many ISP want), let's they follow some
negotiated rulesa and ask another to follow this rules, too.
Alex R (now not ISP network engeneer, through).