Border routers

Richard A Steenbergen ras at
Fri Jul 17 18:55:36 UTC 2009

On Fri, Jul 17, 2009 at 02:19:21PM -0300, Livio Zanol Puppim wrote:
> Thank you guys, This will be useful, but I still have some questions:
> Where can I see comparations between the routers? Also, where can I find
> datasheets containing FIB, RIB and BGP routes limits for cisco and Juniper?
> It is quite dificult!

You won't. All of the numbers published by vendors for such things are 
pretty much complete and total fabrications, and will vary greatly 
depending on platform, code, configuration, what features you have 
turned on, etc.

For example, many people attempting to run code written in the last
couple of years on Juniper M5/M10 have already discovered that they had
to go unofficially hack^H^H^H^H upgrade the FEB DRAM to support their
configuration even though the FIB (in FEB SRAM) was nowhere near
capacity. Also, some routes will consume more memory than others
(consider 1mil unique routes vs 4x paths of the same 250k unique

It is all but impossible to come up with an accurate generic description
of how much horsepower you'll get out of a specific amount of memory,
one would need to know the platform, code, and configuration of your
network to make any kind of educated guess at all. Either find someone
with experience to consult for you, or buy something new and shiny that
is complete overkill and will last you for years. I think the Juniper MX
is the most scalable platform in terms of FIB capacity right now, thanks
to their RLDRAM architecture.

Richard A Steenbergen <ras at>
GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)

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