[c-nsp] Uneven LACP load-balancing

[Brandon Ewing]

On Fri, Nov 12, 2010 at 12:05:07PM -0500, Benjamin Lovell wrote:
> Brandon,
> Just as a side note, "show ip cef exact-route" will show you the software 
> CEF hash. It's not useful on hardware platforms to determine path selection 
> as hardware will not necessarily make the same decision. "show mls cef 
> exact-route" is what you want to use on these platforms. For distributed 
> forwarding(DFC) platforms it may need to be checked by attaching to the 
> ingress LC.
>
> -Ben

show mls cef is not supported on 3560G, unfortunately.  I'm going through my
flowstats attempting to identify a specific flow through the port-channel
that the switch says should use the indicated link, but am currently unable
to locate one.  Does anyone know the default CEF load-sharing algorithm on a
3560G?  I'm thinking of changing it to see if it has an effect.  My fear is
that the switch uses the same hashing method on IPs to select links in both
Layer 2 and Layer 3, resulting in the polarization.

Unfotunately, I don't know if the layer-2 hashing method on src-dst-ip is
independent of whichever CEF algorithm I choose, or if both load balancing
levels always use the same algorithm.

-- 
Brandon Ewing                                        (nicotine at warningg.com)
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