[c-nsp] vs mac table in 3750 switches

[Gert Doering]

Hi,

On Tue, Oct 19, 2010 at 11:54:14AM +0200, Arne Larsen / Region Nordjylland wrote:
> L3sw --trunk--- L2sw1 --trunk--- L2sw2
> 
> It it possible that the L2sw2 switch won't send mac address table updates to the others switches if src and des mac is located on it self.

Classic ethernet switches never "send mac address table updates" (there
is no protocol for that - this will change with TRILL and friends, but
you won't have that).

MAC address tables get updates if switches see packets with yet-unknown
source MAC addresses - and to answer your question: if machines on L2sw2
are talking to other machines on L2sw2, these frames are not sent to
L2sw1, and thus, L2sw1 will not learn these MAC addresses.

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
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