Why do I see all traffic with wireshark when I am using VLAN

[ryank4400]

Hello all, I am not sure if this is an issue for the 9700 but while looking on my network with wireshark I am seeing all of the traffic on the switch, this is happening when I mirror a port that has an IP phone with a PC behind it.

Example:
Vlan 1 is the default vlan on port 1/20
Vlan 20 is the VOIP vlan that is Qtagged on port 1/20
When I mirror port 1/20 or any other that has the same configuration I can see the entire network which would tell me that if this is happening then can that cause quality issues with the VOIP system (OXE R8.0 with 150 4038's) or would this be normal.

Thanks,

[benny]

I really don't understand your question. If you mirror the port, obviously you will see the traffic... ?!

Please be more precise.

-benny

[ryank4400]

Sorry, I have been trying to explain to our new IT administrator that the configuration with the default vlan 1 and tagged vlan 20 would show the traffic but he insists that this should not be. He comes from the Cisco world but to me it is a network thing that would be in any device that is configured the same, I just wanted to be sure that I was correct in telling him that he would see all of the traffic from the two vlans and it seems you are staing this to be true.

Thanks,