Problem to capture Tagged Frames(802.1q)

[escubi]

Hi all,

I’m trying to monitorize the frames that a switch port sends and receives. This port has connected an IP Phone and the frames are tagged(I’m sure).

I have mirrored that port and I capture with a laptot all the traffic but, in the layer 2 part of the paquet, I can’t see the Vlan ID, or the CoS etc…

The faq says that when you monitorize using a mirror you can see the Vlan Information of that paquet…

Here are some details on capturing VLAN tags on various operating systems. If the OS or the network adapter driver won’t allow the VLAN tags to be captured, set up port mirroring (or “port spanning”, as Cisco calls it) on the VLAN switch and connect an independent system, such as a laptop, to the mirror port, and don’t configure the interface attached to that port as a member of a VLAN… You’ll definitely see the VLAN tags, regardless of what OS the independent system is running or what type of network adapter you’re using.

Please, ¿why I cannot view the vlan information of the paquets that I monitorize? The interface attached to that port is member of the native Vlan(logycally).

Regards.