[151185] in North American Network Operators' Group
Re: Shim6, was: Re: filtering /48 is going to be necessary
daemon@ATHENA.MIT.EDU (Ryan Malayter)
Tue Mar 13 07:51:26 2012
Date: Tue, 13 Mar 2012 04:49:39 -0700 (PDT)
In-Reply-To: <4F5EF56D.6070609@necom830.hpcl.titech.ac.jp>
From: Ryan Malayter <malayter@gmail.com>
To: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Mar 13, 2:21=A0am, Masataka Ohta <mo...@necom830.hpcl.titech.ac.jp>
wrote:
> William Herrin wrote:
> >>> When I ran the numbers a few years ago, a route had a global cost
> >>> impact in the neighborhood of $8000/year. It's tough to make a case
> >>> that folks who need multihoming's reliability can't afford to put tha=
t
> >>> much into the system.
>
> >> The cost for bloated DFZ routing table is not so small and is
> >> paid by all the players, including those who use DFZ but do
> >> not multihome.
>
> > Hi,
>
> >http://bill.herrin.us/network/bgpcost.html
>
> > If you believe there's an error in my methodology, feel free to take
> > issue with it.
>
> Your estimate on the number of routers in DFZ:
>
> =A0 =A0 =A0 =A0 somewhere between 120,000 and 180,000 with the consensus
> =A0 =A0 =A0 =A0 number near 150,000
>
> is a result of high cost of routers and is inappropriate to
> estimate global cost of a routing table entry.
>
> Because DFZ capable routers are so expensive, the actual
> number of routers is so limited.
>
> If the number of routes in DFZ is, say, 100, many routers and
> hosts will be default free
For quite some time, a sub-$2000 PC running Linux/BSD has been able to
cope with DFZ table sizes and handle enough packets per second to
saturate two or more if the prevalent LAN interfaces of the day.
The reason current routers in the core are so expensive is because of
the 40 gigabit interfaces, custom ASICs to handle billions of PPS,
esoteric features, and lack of competition.
The fact that long-haul fiber is very expensive to run limits the
number of DFZ routers more than anything else. Why not take a default
route and simplify life when you're at the end of a single coax link?
If your lucky enough to have access to fiber from multiple providers,
the cost of a router which can handle a full table is not a major
concern compared with your monthly recurring charges.
--
RPM
