[c-nsp] Speed problem and router seems to sluggish

[Gert Doering]

Hi,

On Mon, Jun 28, 2010 at 09:14:58AM +0700, Rudy Setiawan wrote:
> I'm hoping to get in touch with the vendor on Monday and try to get a
> DFC3BXL sent over.
> 
> True, I did not see anything in the log that said about tcam stuff. On our
> border1, it did show that since I was using a sup2 engine and receiving a
> full routing table + private peerings. the cpu on border1 was around 30% on
> the average.
> 
> Jun 19 20:33:08.311 PDT: %MLSCEF-SP-7-FIB_EXCEPTION: FIB TCAM exception for
> IPv4 unicast, Some routes will be software switched.
> Use "mls cef maximum-routes" to modify FIB TCAM  partition.

Well, this is the message that you don't want to see on your Sup720 systems
- it basically tells you that the TCAM overflowed and that you'll have
problems now, until you reboot.

The architecture of Sup720 and Sup2 are fundamentally different as to
"what happens when TCAM is full".  On the Sup2, you'll "just" software-
switch packets - so you have high CPU load, but if the CPU can keep 
up, packets will still flow.  

On the Sup720, these packets will also be subject to rate-limiting, so 
you'll also have packet loss for those prefixes that go to software
switching.  *And* high CPU, if the traffic levels are high enough.

gert
-- 
USENET is *not* the non-clickable part of WWW!
                                                           //www.muc.de/~gert/
Gert Doering - Munich, Germany                             gert at greenie.muc.de
fax: +49-89-35655025                        gert at net.informatik.tu-muenchen.de
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