Re: FW: /8s and filtering

[bmanning () vacation karoshi com]

 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