To add to Matt's comments below, impact will depend on card engine, software rev level, and sampled vs regular netflow. Sure your local SE can help you clarify how "significant" of an impact it would be.
Matt
At 03:06 PM 2/21/2001 -0500, Matthew Davy wrote:
>On Wed, Feb 21, 2001 at 02:12:30PM -0500, Chris Rapier wrote:
>> > We hope to package up the Netflow portion (sans ResNet database) to run
>> > under Linux. So someone could drop it on generic Linux machine, configure
>> > their router to export netflow
>>
>> Question about the usage of netflow, aside from the lisencing fees
>> doesn't enabling it on a router produce a noticable performance hit? I
>> know that hit can be mitigated by sampling instead of monitoring every
>> packet but how are you getting accurate data on usage that way?
>> Admitedly I don't know much about netflow as we'd never bothered with
>> getting a license for it.
>
>The performance impact most likely depends on what type of router you're
>running. I just read some documentation on the Cisco 6509 that claims
>there's no impact. On the other hand, I've been told there's a significant
>impact on GSRs. On Junipers you're limited by the 100mbps connection to
>the Routing Engine.
>
>- Matt
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