[nsp] HSRP multicast & switch ports

Jochen Kaiser Jochen.Kaiser at rrze.uni-erlangen.de
Thu Sep 4 18:46:55 EDT 2003

On Wed, Sep 03, 2003 at 11:10:07AM +0800, John Wong, Kok Seng wrote:
> How do we prevent HSRP multicasts ( being flooded
> out ALL switch ports? We're running HSRP on Cat6500 MSFCs
> and we're seeing the HSRP multicast packets on all the ports
> in the HSRP VLAN connected to the switch.

The flooding is not only done for the routers. It's also needed for the
switches to make them learn where they can find the new originator
of the virtual MAC address. By this they can update their CAM tables 
with a single 'sweep'.
IMHO if you disable the flooding, it will take your switchtes longer to
learn this.


Dipl. Inf. Jochen Kaiser, GPG 0x3C93A870, phone +49 9131 85-28681
Network Administration  mailto:jochen.kaiser at rrze.uni-erlangen.de
Regionales Rechenzentrum Universitaet Erlangen-Nuernberg, Germany
Homepage and PublicKey: http://ipv6.rrze.uni-erlangen.de/~unrz111 

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