nanog mailing list archives

Re: Cisco uRPF failures


From: "Anton Kapela" <tkapela () gmail com>
Date: Sat, 6 Sep 2008 12:20:34 -0500

On Thu, Sep 4, 2008 at 11:35 AM, Jo Rhett <jrhett () netconsonance com> wrote:

That's the surprising thing -- no scenario.  Very basic configuration.
 Enabling uRPF and then hitting it with a few gig of non-routable packets
consistently caused the sup module to stop talking on the console, and

What do you mean by 'non routable?'

What was the src/dst makeup of the test traffic?

We also discovered problems related to uRPF and load balanced links, but
those were difficult to reproduce in the lab and we couldn't affect their
peering, so we had to disable uRPF and ignore so I don't have much details.

What version of code? Also, port-channel/lag or ECMP?

quickly, but that turns out not to be the case.  To this day I've never

I've never seen the issues you speak of, so it could be
code/platform/config specific.

Also, what sup were you testing?

found a network operator using uRPF on Cisco gear.
 (note: network operator. it's probably fine for several-hundred-meg
enterprise sites)

Forgive me, but what does bits/sec have to do with anything?

-Tk


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