New data point: the problem only occurs when the haldaemon is running. 
What, I wonder, does that daemon do with the network interfaces?

cheers,

Steve Gaarder
System Administrator, Dept of Mathematics
Cornell University, Ithaca, NY, USA
[log in to unmask]

On Thu, 14 Jun 2007, Steve Gaarder wrote:

> I just installed SL for the first time on an Intel Core Duo box with an MSI 
> G965M-FIR motherboard. This board has a Realtek RTL-8169SC network inteface 
> that uses the r1000 driver.  Pings show a bizarre pattern.  If I ping every 
> 10 seconds, the turnaround time gradually increases with each ping until it 
> hits about 2 seconds, at which point it drops back to a low value and starts 
> climbing again.  If I ping every second, I see the increasing behavior also, 
> with every other ping taking an extra second.
>
> Any clues?
>
> Steve Gaarder
> System Administrator, Dept of Mathematics
> Cornell University, Ithaca, NY, USA
> [log in to unmask]
>