[54127] in North American Network Operators' Group
Re: FW: /8s and filtering
daemon@ATHENA.MIT.EDU (bmanning@vacation.karoshi.com)
Tue Dec 10 17:12:14 2002
From: bmanning@vacation.karoshi.com
To: hnarayan@cs.ucsd.edu (Harsha Narayan)
Date: Tue, 10 Dec 2002 14:11:39 -0800 (PST)
Cc: bmanning@vacation.karoshi.com,
hnarayan@cs.ucsd.edu (Harsha Narayan), nanog@merit.edu
In-Reply-To: <Pine.GSO.4.32.0212101358500.4939-100000@gradlab.ucsd.edu> from "Harsha Narayan" at Dec 10, 2002 02:03:17 PM
Errors-To: owner-nanog-outgoing@merit.edu
Clue! - as you know doubt are now aware, VERIO and Jippi are -two-
of the tens of thousands of ISPs that make up the catanet that is the
Internet. The published filtering policies of these two providers is
a useful tool for others to determine why VERIO and Jippi are contributing
to "odd" routing.
WRT learning more, you may wish to review the IETF's CIDRd WG archives
from 1993-1997. You may also wish to review RFC 2050 and the various
RIR policies on the evolution of that work.
>
> Hello,
> Yes, it is all classless now, but I saw Verio's policies and thought
> that it is the way ISPs filter. Also, the Jippi group filters at /21
> except in the 192.0/7 space (where it is a /24). I didn't have enough
> knowledge to realize that classful was "vestigal".
>
> Thanks,
> Harsha.
>
> On Tue, 10 Dec 2002 bmanning@vacation.karoshi.com wrote:
>
> >
> > but there is no "class C space" anymore. there is no "class A space"
> > either. its all CIDR space and some providers have retained some
> > vestigal classfull concepts in the creation/maintaince of their routing
> > filters. a /24 may or may not get you past my filters. any you'll have
> > no way to know until/unless you try to get to my sites or we develop
> > a peering relationship.
> >
> > wrt the evolution of filters. yes, they do evolve. and so does ARIN
> > policy. you presume too much to second guess that ARIN policy will
> > evolve in the way you outline.
> >
> >
> > >
> > > Hello,
> > > Thank you very much everyone for all your replies. When Class C space
> > > gets used up, wouldn't the filtering policies have to change to allow the
> > > same kind of multihoming from the Class A space. Currently, a /24 from
> > > Class C is enough to get past filters. However later, a /22 (or is it /20)
> > > from Class A would be required to get past filters.
> > >
> > > Since there are only three /8s left in Class C, I was curious whether
> > > filtering policies would change to accommodate this.
> > >
> > > If filtering policies won't change ARIN will have to change its
> > > multihoming PA policy to giving away a /22 instead of a /24. Though
> > > officially it is RIR policy not to worry about the routability of an
> > > a prefix I guess they do worry about it?
> > >
> > > Thanks,
> > > Harsha.
> > >
> > >
> > > On Tue, 10 Dec 2002 bmanning@vacation.karoshi.com wrote:
> > >
> > > > >
> > > > >
> > > > > Hello,
> > > > > Now I am confused because I have got two sets of contradicting answers.
> > > > > Some say that anyone can multihome, some say that you need to be of a
> > > > > certain minimum size to multihome. May I know what is the right answer?
> > > > >
> > > > > I agree that allowing anyone to multihome would increase the size of the
> > > > > routing table. So does this mean that someone has to be of a certain size
> > > > > to multihome?
> > > > >
> > > > > Harsha.
> > > > >
> > > >
> > > > anyone can multihome, with the cooperation of others.
> > > > current practice seems to dictate that the standard
> > > > operating procedures to protect the integrity of
> > > > the routing system mandate that only prefixes of
> > > > certain lengths are allowed at -SOME- isp boundaries.
> > > >
> > > > you seem to have the assumption that there is a single
> > > > standard here. There is not.
> > > >
> > > > --bill
> > > >
> > >
> > >
> > >
> > >
> >
>
