[f-nsp] Multicast causing high CPU

[Dimitar Kosadinov]

On Tue, 10 Mar 2009 13:33:08 +030
How many multicast traffic and do You have secondary ip address on ve interface ?


Alexey Kouznetsov <foundry-list at kouznetsov.com> wrote:

> Hello!
> 
> Yes, it is IronCore, not Jet
> 
> /Alexey
> 
> 2009/3/7 Peter Olsen <Peter.Olsen at globalconnect.dk>
> 
> >  Is it IronCore mgmt module ?
> >
> > If yes, it is properly even worse.
> >
> > We discussed this in legth with foundry. To my opinion it is a design bug:
> > stating wire speed packet forward performance and then having limitations
> > like this.
> > I don't know if there is a fix for you. But we gave up in the end, and as
> > we for other reasons as well needed bigger boxes we have replaced nearly all
> > JetCore with XMR/MLX
> >
> >
> > *Med venlig hilsen/Best regards
> >
> > **Peter Olsen
> > **CTO
> > **D: +45 7730 3122
> > **M: +45 2726 3122
> > *
> >
> >
> >  ------------------------------
> > *From:* Alexey Kouznetsov [mailto:foundry-list at kouznetsov.com]
> > *Sent:* 7. marts 2009 14:58
> > *To:* Peter Olsen
> > *Subject:* Re: [f-nsp] Multicast causing high CPU
> >
> >   Thank you, for your replay Peter!
> >
> > This is no Jet core... AFAIK Jet core will be J-BxGMR4 and CPU protection
> > is not available in our version. As far as I can see it takes 100%CPU at
> > less 10kpps, not 200k
> > Active management module:
> >   466 MHz Power PC processor 750 (version 8/8302) 66 MHz bus
> >   512 KB boot flash memory
> >  8192 KB code flash memory
> >   256 KB SRAM
> >   256 MB DRAM
> > So, As far as I  can see only hardware upgrade is the possible solution ?
> >
> > /Alexey
> >
> > 2009/3/7 Peter Olsen <Peter.Olsen at globalconnect.dk>
> >
> >>  JetCore FPGA can handle around 200.000pps broadcast/multicast before you
> >> have ~80-100% CPU load as far as L2 is concerned
> >> All packets is handled by CPU by default.
> >> You can play around with the CPU protection features but to my experience
> >> it have limited impact (and limited success as far as CPU load is concerned)
> >> I guess this is kind of architecture limitation in JetCore.
> >>
> >> It is even worse if you have the same mac adress arriving from two
> >> different directions, e.g. hitting two port at the same time. (will happen
> >> if you have a L2 loop), then 99% CPU load will happen at very load pps. In
> >> this case it is caused by the mac learning process eating all CPU
> >> resources. This behaviour makes JetCore L2 very sensitive to layer2 loops.
> >>
> >> For us it was first efficiently fixed going to MLX/XMR where
> >> CPU-protection feature is very efficient and you can force all
> >> braodcast/multicast packets to stay in hardware for forwarding. XMR/MLX can
> >> also handle much more than 200.000pps in CPU
> >>
> >> br,
> >> Peter
> >>
> >>
> >
> 


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