[c-nsp] unicast NFS traffic seen on all trunks

[Gert Doering]

Hi,

On Wed, Jan 17, 2007 at 08:05:32AM -0800, Kevin Howard wrote:
> Example:  Core A and B.  Spokes C,D,E,F,G
> 
> traffic passes from C to core (A/B) back to D.  The trunk links on E, F, & G 
> see the traffic.
> Any input on this or where else to look would be appreciated.

This could happen if the traffic is asymmetric

 C->A->D
 D->B->C

in that case, neither "A" nor "B" knows the MAC address for the 
destination host (because it doesn't see traffic from that host),
and has to flood the traffic.

Now I'm not sure whether this could happen in a pure layer2 cloud,
but it's something you might want to check for - make sure that 
the mac addresses for your NFS hosts (both source and dest MAC)
are visible in the CAM tables for the core switches that the traffic
traverses.

gert
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Gert Doering - Munich, Germany                             gert at greenie.muc.de
fax: +49-89-35655025                        gert at net.informatik.tu-muenchen.de