Allied Telesis AT-S60 - Manual (Page 491)

Chapter 32: Port Mirroring
Section IV: Web Browser Management 490
The Add New Mirror page is displayed as shown in Figure 180.
Figure 180 Add New Mirror Page
5. Click the ports in the graphical switch image.
Click once for S, which stands for the source mirror port. Click
twice for D, which stands for destination mirror port. Click three
times to deselect a port.
6. Click Apply.
The Port Mirroring tab is displayed. It reflects the changes you
made in Step 6. The port mirror is immediately activated on the
switch.
To save your changes, return to the General tab and click Save
Changes
You can connect a data analyzer to the destination mirror port to
monitor the traffic on the selected ports.