[c-nsp] sup720 ICMP redirects "once per second"

Pete Lumbis alumbis at gmail.com
Tue Feb 12 08:06:16 EST 2013

>From what I could dig up, yes, 1 per second, rate limited on a
per-interface basis.

>From a CEF point of view, when we do the lookup and realize we have to do a
redirect we punt to process switching. From the 6k perspective this would
be a specific punt to software that would be matched against the MLS rate
limiter. At that point the ICMP code looks at the input interface and the
last time a redirect was generated on that interface to determine if a new
redirect should be generated.


On Tue, Feb 12, 2013 at 4:46 AM, Phil Mayers <p.mayers at imperial.ac.uk>wrote:

> On 02/12/2013 02:34 AM, Pete Lumbis wrote:
>> I'm pretty sure this is statically defined within IOS for all redirects
>> on an given interface.
> So it's 1 redirect per second per input-interface, not configurable?
> If it's an IOS-wide behaviour, that implies it's not platform specific,
> which would make sense, and ties with my original understanding of the way
> redirects are handled on this platform (all packets to sup, sup forwards in
> software).

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