Draytek Vigor 3200 Series User Manual page 147

Available settings are explained as follows:
Item
Port Mirror
Mirror Port
Mirrored port
After finishing all the settings here, please click OK to save the configuration.
Description
Check Enable to activate this function. Or, check Disable to
close this function.
Select a port to view traffic sent from mirrored ports. At
present, only WAN4 will be treated as mirror port.
When Port Mirror is enabled, the Mirror Port (WAN4) will
be disabled.
Select which ports (LAN port or WAN port) are necessary to
be mirrored. P1 represents LAN port.
137 Vigor3200 Series User's Guide