route filtering policies (from "split b" thread)

[Pete Bowden]

A customer that has a /24 from you will have a hard time justifying a /20 or 
21 to ARIN.  You're right, in the case of a failure, there may be issues...  
and ARIN doesn't guarantee that routes of any size will be announced or 
accepted anywhere on the net.  If you are willing to accept your own 
announcements from others then you might still have a route to your customer 
when your circuit goes down via their other provider... that's your 
choice...  Announcing the entire internet as /24's just isn't scaleable, and 
the needs of the large players are sometimes at odds with the desires of 
smaller providers or collocation/server/hosting providers -- who are more
likely to make that sale on the type of one-off or exception, where many of
the larger players will just say that they can't guarantee that a dual homed
connection will work in the case of either providers circuit failing.  

> 
> Let's start with the fact that my customer also has to be seen out the OTHER
> ROUTE that belongs to ANOTHER vendor. If we agregated the customer then we
> announce him even when his line to us is down. It has gone done once in the
> last year and it took the local ILEC over nine hours to fix it. His route to
> me MUST disappear when I am not carrying him so that all traffic will flow
> to the other vendor who is announcing the /24 as well.
> 
> He can't afford to be down for nine hours - his line to the other Vendor has
> failed three times in the last years for a total out of server duration of
> four days - and that's Sprintlink.
> 
> So indeed there is a need for him to lie so that he can get a block that
> will route if filters are going to drop him.
> 
> /* Mike Lieberman                            Mike at NetWright.Net */
> /*                         President                            */
> /*                       Net Wright LLC                         */
> /*                   http://www.netwright.net                   */
> /*                 Voice and Fax: 307-857-1053                  */
> 
> > -----Original Message-----
> > From: Pete Bowden [mailto:repete at cncx.com]
> > Sent: Monday, June 05, 2000 5:06 PM
> > To: Mike at netwright.net
> > Cc: arin-discuss at arin.net
> > Subject: Re: route filtering policies (from "split b" thread)
> >
> >
> > Yes, but in your case you should be announcing your larger agregate...
> > so...  since your customer should still be reachable from you
> > if the route
> > is filtered they will not see the more specific and will see
> > the agregate
> > and route the block to you...  you in turn will hand it over
> > to your customer.
> > No need for them to lie about anything....  you just need to
> > make the case to
> > them that this is how it works for technical reasons beyond
> > your ability to
> > control -- technical reasons being limiting bandwidth and
> > other providers
> > not feeling like they should be compelled to provide free
> > passage of other
> > peoples blocks.
> >
> > >
> > > This conversation about filter leaves me scratching my head.
> > >
> > > Some of you are making a specific assumption that only
> > large bandwidth, large
> > > block users must multihome between various providers. While
> > I do not argue
> > > that this is the most common situation, it is not the only
> > situation.
> > >
> > > We support one company that is currently multi-homed
> > between two providers
> > > and will likely be adding a third. No line is larger than a
> > T1. The customer
> > > barely needs a /24. So we provide the customer a /24. He
> > then announces this
> > > network to his other vendor as well as through us.
> > >
> > > If this customers routes get filtered because the company's
> > address block
> > > isn't large enough, the only thing you are doing to placing
> > pressure on the
> > > customer to fake the need for more IP addresses so that
> > their network gets
> > > announced and carried by more networks. Am I the only one
> > who thinks that
> > > such filtering policies are counter intuitive?
> > >
> > > The need to preserve IP space is at odds with the needs to
> > hold down the size
> > > of the BPG announcements. ARIN members needs to make a
> > choice. I don't like
> > > rules that force my customers to lie to me or suffer poor routing.
> > >
> > > /* Mike Lieberman                            Mike at NetWright.Net */
> > > /*                         President                            */
> > > /*                       Net Wright LLC                         */
> > > /*                   http://www.netwright.net/                  */
> > > /*                 Voice and Fax: 307-857-1053                  */
> > >
> >
> >
> > --
> > Pete Bowden, Internet Network Engineer, Internet & Data
> > Center Engineering
> >     rePete at concentric.com  rePete at cncx.com  pete at internex.net  NIC:PB8
> > Concentric Network Corporation, 1400 Parkmoor Ave., San Jose,
> > CA  95126-3429
> > 		  Voice: 408-808-6010    Fax: 408-808-6010
> >
> 


-- 
Pete Bowden, Internet Network Engineer, Internet & Data Center Engineering
    rePete at concentric.com  rePete at cncx.com  pete at internex.net  NIC:PB8
Concentric Network Corporation, 1400 Parkmoor Ave., San Jose, CA  95126-3429
		  Voice: 408-808-6010    Fax: 408-808-6010