nanog mailing list archives

Re: FW: /8s and filtering


From: N <nathan () stonekitty net>
Date: Tue, 10 Dec 2002 13:11:52 -0800


On Tue, Dec 10, 2002 at 12:45:42PM -0800, Harsha Narayan wrote:
    2) Small multihomers must get the ISP that assigns them address space to
allocate them at least a /24 (with multihoming as the justification if
needed). The ISP must agree to allow them to advertise their allocation
through other providers and must agree to hear and announce the block from
the customer *and* *other* *ISPs*.

Hello,
Doesn't this mean that unless filtering policies change, after Class C
space is used up, the multihomer will have to get a /22 from the ISP
(since after Class C gets used up allocations will be made from Class A
space). There are only three /8s left in the Class C space.

To be accepted into Verio's space per the URL that
forrest () almighty c64 org pasted... you are correct.  I still think this
is a rare method of filtering... and perhaps Verio will change their
policy to be /24 everywhere once the Classfull C ranges are gone. As
others have mentioned... not all providers filter in the same way, and
sometimes the methods are not published..... Its relatively safe to
make a *vague* judgement that a /24 will get you reachable via *most* of 
the net.  
-- 
,N

~Nathan - routing & switching dude/fly-boy/sport biker - San Jose CA~


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