[c-nsp] GSR Engine 0 and Engine 1 Limitations - Loose RPF and NetFlow

[Jared Mauch]

On Tue, Jun 27, 2006 at 06:54:26PM -0500, Adam Kujawski wrote:
> I would like to enable loose unicast RPF on an Engine 0 line card, but
> am not sure what kind of performance hit to expect (if any). I think
> the ASIC-based line cards can handle RPF checks w/o a problem, but not
> sure about the older cards.

	For engine0, expect roughly a 50% decrease in performance,
or only being able to attain 50% of line-rate.  This is fine if you
are not using all the ports on the card possibly.  This requires
intelligent engineering and part of my "know your hardware" mantra :)

	I do encourage the use of at least the loose rpf and the strict
RPF whenever possible (ie: if you're operating an enterprise network,
there is no reason you should not enable the strict RPF
facing your firewall/DMZ lan).

> Also, I would like to start using sampled NetFlow on an engine 1 line
> card. Has anybody looked at the performance impact of a 1/1000
> sampling rate on an Engine 1 line card?

	(don't know here, sorry)

	- jared

-- 
Jared Mauch  | pgp key available via finger from jared at puck.nether.net
clue++;      | http://puck.nether.net/~jared/  My statements are only mine.