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Re: Pentium IV router vs. Cisco router



On Sun, February 26, 2006 21:23, Andrew Miehs said:
>
> [..]
>
> PS: I prefer using real routers, as they can switch packets in their
hardware...
> You may even want to look at a 26xx as that should probably be fast
enough if you
> only want 2 ethernets, and are doing fast switching....

[given the previous posts, I assume that we're actually talking about fast
ethernet here - if you ment 10mbit ethernet instead, please disregard my
post]

if you need to move 'real' 100 mbit/sec, this is not a good idea.

cisco specifies a 2651XM with 20,5 MBit/sec (40kpps), a 2691 with 35,8
MBit (70kpps) at 64 byte packet size [0].
this is without any features (QoS, ACLs, ..), pure static IP routing only
(and probably inclusive some marketing-optimism ;-)
so, for real life usage you will have to subtract at least 20-30% from the
pps numbers, depending on what the box needs to do.

while you can get higher throughput numbers with larger packet sizes, you
should think about what happens during a (DoS)-attack. a single FE port
can get 110kpps delivered to your router at minimum packet sizes..

in general, the fact that any given cisco router has a interface with
interface speed X does not neccessarily mean that it can also forward
packets at speed X. (take 3845 for example - it is equipped with 2
GigE-ports onboard, but can handle around 200mbit; or a NPE-G1 with 3x
GigE onboard, which will die happily if you try to push more then 300mbit
through it with some basic features enabled)

regards,
-jr

[0]
http://www.cisco.com/warp/public/765/tools/quickreference/routerperformance.pdf



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