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Re: Public ASs [7:84390] posted 02/15/2004
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At 01:34 PM 2/15/2004, woky wrote:
>Danny Cox wrote:
> > Thanks Joseph - that's smaller than I'd expected;  I am
> > considering something even smaller.  We have a need to
> > create a system which is as resilient as possible from a routing
> > point of view.  I really want to use two ISPs and therefore
> > portable addresses, though the number of IP addresses, at least in
> > the short term, will not be much bigger than a /24 or /23 at the
> > largest though it may well grow.
> >
> > I have read suggestions that IP addresses get aggregated into
> > larger blocks than that typically for routing table efficiency
> > - I saw suggestions of /19 as a minimum -  but also that there
> > have been some changes to this.
> >
> > I'd hate to find that we put together a dual ISP
> > setup, join RIPE, get the portable addresses etc to find that the
> > routing disappears because the larger ISPs won't accept them or
> > that I can't get an AS number because we're too small.  It seems
> > to me this would likely to be quite a common scenario, and if I
> > am right that it is, I am confused that there are still AS numbers
> > available.  Are there other techniques for small-system
> > multi-homing other than multi-ISP/BGP/PA setups of which I'm just
> > not aware ?
> >
> > I don't think there's any technical reason why any of this is very
> > onerous, but there might be policy reasons and I'm not sure where
> > to go to clarify this.  Very happy to read anything which makes
> > the policies of all this clearer if anyone can give me any pointers?
> >
> > Many thanks
> >
> > Danny
>Many tier 1 providers will not accept /24 advertisements, period - NTT
>Verio IIRC will not accept any advertisements smaller than /22 from any
>non-customer (IE: someone not using them as a direct provider). I'd
>suggest reading NANOG ( for more
>high-level discussions of such topics, but bring your flame-retardant
>underwear - it seems far more flame-ridden nowadays than it once was.

Hey Robbie,

Can you name another?  Last I checked, Verio accepts /24s and I'm not aware 
of anyone else who filters.  Your points are dead on though.  I just think 
that the Verio argument is becoming stale.


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