FW: NAT CEF

-----Original Message-----
From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
Carlos G Mendioroz
Sent: Sunday, May 23, 2010 3:02 PM
To: swap m
Cc: Maarten Vervoorn; Cisco certification
Subject: Re: NAT CEF

FTR, the 12.2(14)SX release notes paragraph:

Prior to Cisco IOS Software Release 12.2(14)SX, the NAT function on the
Cisco Catalyst 6500 Series Switch was performed in software and bound to the
capacity of the route processor. With the Cisco Supervisor 720 and PFC3,
coupled with Cisco IOS Software 12.2(14)SX, the NAT function is now hardware
assisted for increased performance and scalability.

So it seems that the PFC3 can do this, I assume a 7600 can/will too.

Interesting, I've been talking about CEF for ages, and just this year I've
started to link some loose ends. Like it supporting L4 stuff when it is
advertised as an advanced L3 mech.
Has anybody some doc on how is CEF implemented in different archs ?
I've learned that is software on some, more hardware on others, but I guess
that the API is more or less the same on all.

I had thought that all L4 features just where implemented as ACLs punting
the traffic to the proc, but it seems that's not the case.

-Carlos

swap m @ 19/05/2010 13:59 -0300 dixit:
> yeah sure, and i must add tht its mandate to have a new IOS supporting
> the hardware switching for nat. newer trains in 12.2SX series support
> hardware nat switching.
>
> On Wed, May 19, 2010 at 8:15 PM, Carlos G Mendioroz <tron_at_huapi.ba.ar>
wrote:
>>
>> swap m @ 19/5/2010 11:43 -0300 dixit:
>>> For 5-6Mb traffic, you can safetly use NAT.
>>>
>>> on 6500, NAT translation creation is software switched, the flow
>>> afterwards is still on hardware.
>> Are you sure about this ?
>> -Carlos
>>
>>> IP nat outside doesnt affect other traffic that doesn't match NAT
>>> rule. Other traffic is hardware switched as if NAT is not configured.
>>> And in case you feel the traffic rate will be high in future, you
>>> can always put a NAT ratelimit, that'll ensure the box doesnt die.
>>>
>>> Swap
>>> #19804
>>>
>>> On Wed, May 19, 2010 at 6:14 PM, Maarten Vervoorn
>>> <mr.vervoorn_at_gmail.com>
>>> wrote:
>>>> Only a small part of that traffic is needed to be translated.
>>>> 5-6Mbit. So is it the case that when you configure ip nat outside
>>>> on a interface all traffic will be softare switched from that
>>>> interface?
>>>>
>>>> 2010/5/19 Tyson Scott <tscott_at_ipexpert.com>
>>>>
>>>> Maarten,
>>>>> I would recommend taking this up with your account rep. That is a
>>>>> lot of traffic to be software switched.
>>>>>
>>>>> Regards,
>>>>>
>>>>> Tyson Scott - CCIE #13513 R&S, Security, and SP Technical
>>>>> Instructor - IPexpert, Inc.
>>>>> Mailto: tscott_at_ipexpert.com
>>>>>
>>>>>
>>>>>
>>>>> -----Original Message-----
>>>>> From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On
>>>>> Behalf Of Maarten Vervoorn
>>>>> Sent: Wednesday, May 19, 2010 9:41 AM
>>>>> To: Cisco certification
>>>>> Subject: NAT CEF
>>>>>
>>>>> Hi group.
>>>>>
>>>>> For the mirgation of a very important business application we want
>>>>> to use NAT to migrate every connection of that application to the
>>>>> new IP address.
>>>>> The networks are configured on a 6500 sup720 switch. I read the
>>>>> Cisco documentations and noticed that NAT translation had to be
>>>>> done in software.
>>>>> The outside NAT interface or on a 20Gbit connections (these are
>>>>> avarage loaded with 1-5Gbit. Will the configuration of NAT degrade
>>>>> my performance?
>>>>>
>>>>> Kind regards,
>>>>>
>>>>> Maarten Vervoorn
>>>>>
>>>>>
>>>>> Blogs and organic groups at http://www.ccie.net
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>> --
>> Carlos G Mendioroz <tron_at_huapi.ba.ar> LW7 EQI Argentina
>
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--
Carlos G Mendioroz  <tron_at_huapi.ba.ar>  LW7 EQI  Argentina
Blogs and organic groups at http://www.ccie.net