[c-nsp] RPF on 6500

[RawCode]

On 5/22/05, Tim Stevenson <tstevens at cisco.com> wrote:
> At 06:08 AM 5/22/2005, RawCode gushed:
> >Is there a performance difference between the two methods (rx | any)
> >of turning on RPF on a 6500?
> 
> No, same performance impact (ie, none). Do note that you can't mix/match
> modes on different i/fs, all i/fs use the last configured mode, strict or
> loose.
> 
> >  Also is there a performance hit if you
> >enable an access-list for the RPF?
> 
> Yes, softwware performance - this is not supported in the h/w.
> 
> >   How would this compare to just
> >using an access-grouped interface?
> 
> access-group gets h/w enforcement, so the choice is clear...

Interesting that the access-group will hinder performance less than rfp w/ ACL.


> 
> >The 6500 is currently using 12.1(23) with a Sup2 and PFC2 and MSFC2.
> 
> Note that enabling uRPF check on sup2/pfc2 halves your total available FIB
> TCAM.

I don't think this will be an issue for this device.

sh mls cef sum

Total CEF switched packets:  0000057819597928
Total CEF switched bytes:    0029638731197779
Total routes:                2548
    IP unicast routes:       2548


> 
> >I understand that the PFC2 will handle packets that have a single
> >return path, and any others will be passed onto the MSFC2.
> 
> In strict mode, yes, that's correct.
> 
> Tim
> 
> 
> >This
> >shouldn't be too much of an issue since the 6500 is acting as our
> >aggregation point for dsl and dial platforms so it is a pretty single
> >path environment.
> >
> >TIA!
> >
> >Mike Gonnason
> >
> >_______________________________________________
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> 
> 
> 
> Tim Stevenson, tstevens at cisco.com
> Routing & Switching CCIE #5561
> Technical Marketing Engineer, Catalyst 6500
> Cisco Systems, http://www.cisco.com
> IP Phone: 408-526-6759
> ********************************************************
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> 

Mike Gonnason