[j-nsp] NAT without AS PIC

[Andrey Zarechansky]

On Thu, Aug 07, 2008 at 02:36:32PM -0300, Rubens Kuhl Jr. wrote:
> >> On the 7600 and the ASR1000, is that hardware accelerated NAT a
> >> default option, or are those add-on features?
> >
> > On both the 7600 and the ASR it is in the base images and ready to
> > just configure.  Crazy for Cisco, I know.  You'd think they'd milk
> > another license out of you somewhere. :)
> 
> That doesn't mean it's healthy to do  NAT, because every first packet
> of a flow will hit a slow CPU (unless you have brand new RSP720).

Slow CPU will just limit connection setup rate:
- first packet will hit NAT rule on the MSFC and will create session hash
- MSFC will upload Netflow TCAM action to the PFC3
- first reply packet will hit NAT session hash on the MSFC
- MSFC will consume another one Netflow TCAM entry within PFC3
- the whole ongoing packet sequence will hit Netflow TCAM entries and
  packet processing will handled by PFC3.`

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ZA-RIPE||ZA1-UANIC