capturing traffic for all vlans

Unanswered Question
Apr 27th, 2009

Hi all, If I want to capture all the broadcast traffic for all vlans, i set the port my pc plugs into as a trunk. would this work ok ?

I have this problem too.
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Giuseppe Larosa Mon, 04/27/2009 - 00:51

Hello Carl,

no it is the source definition that defines what you can capture not the destination port settings

You need to declare the list of vlans in the monitor source section.

I wouldn't do so because the destination port is easily overwhelmed (total traffic can be much more then port rate)

This can be a problem for the switch.

Even c6500 can have cpu at 100% in case of high oversubscption of a destination port.

So be careful!

Hope to help


carl_townshend Fri, 05/01/2009 - 01:42

so are you saying my pc will receive the traffic for all the vlans on that port ?

Giuseppe Larosa Fri, 05/01/2009 - 03:40

Hello Carl,

I was trying to advice that this can lead to further problems when there is heavy oversubscription of the span destination port = mirrored traffic is much more then output port speed.

Hope to help



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