[c-nsp] Question on the Use of Policy Based Routing

[Gert Doering]

Hi,

On Wed, Mar 07, 2012 at 04:07:03PM +1100, Andrew Miehs wrote:
> >> Does PBR still cause the performance issues it did in the past, forcing every packet through the CPU?
[..]
> Just found my own answer!
> 
> http://www.cisco.com/en/US/docs/ios/12_0/qos/configuration/guide/qcpolicy.html
> 
> "IP PBR can now be fast-switched. Prior to Cisco IOS Release 12.0, PBR could only be process-switched, which meant that on most platforms the switching rate was approximately 1000 to 10,000 packets per second. This speed was not fast enough for many applications. Users who need PBR to occur at faster speeds can now implement PBR without slowing down the router."

Well, that answer is relevant for software-forwarding platforms, where
"can use CEF!" will indeed bring a major performance boost.

Unfortunately, it's fully irrelevant for the 3750 in use here, as it's
CPU is tiny and "can use CEF" doesn't tell wether the hardware forwarding
machinery can handle PBR or not.


As for the original question: sounds like an attempt to ensure job security 
to me...  "make the setup so convoluted that nobody else can manage it".

If management needs to use some other routing than production traffic,
well, then use "ip local policy" for management traffic (or a management
VRF).

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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