It does indeed support this feature.
To select the output port, where you connect the packet sniffer, use the command
where <port> is the port you want to use for the output.
To select the ports you want to monitor, use the command
<b>interface ethernet < monitor-list > monitor</b>
where: < monitor-list > includes port numbers and static trunk names such as a4, c7, b5-b8, and trk1.
To turn either of these off, prefix the command with '<b>no</b>'.
These are also available through the web interface, but the CLI is an easy way, and the way that I configure any of these switches.
Hope this helps.