FW: /8s and filtering

Harsha Narayan hnarayan at cs.ucsd.edu
Tue Dec 10 18:47:29 UTC 2002

  I had the same questions. Could someone please answer these?


On Tue, 10 Dec 2002, Forrest wrote:

> >
> > >I was also curious about this - if I am a customer who wants to
> > >multihome and can justify only a /24, I would go to an ISP which has an
> > >allocation from the Class C space rather than one from the Class A
> > >space.
> >
> > 	It doesn't matter. For all practical purposes, basement multihomers
> > only
> > care that their two or three providers have their route.
> Maybe I'm missing something, but what good would it do for someone to
> multihome if only their own providers accept their route, but nobody else
> does?  I realize that their block should be still announced with their
> ISP's larger aggregate, but what good does this do if your ISP goes down
> and can't announce the large aggregate.
> If you're a smaller organization, perhaps you'll only have a /23 from your
> upstream provider.  With the filtering that seems to be in place, it seems
> like the only way you can truly multihome with a /23 is if it happens to
> be in the old Class C space.  Or is this wrong?
> What seems to be needed is perhaps a /8 set aside by the RIR specifically
> to allocate to small organizations that wish to multihome that people
> would accept /24 and shorter from.
> Forrest

More information about the NANOG mailing list