Dahua DH-PFS4218-16GT2GF-240 Manual page 33

Step 4 Select 3 ports at least to combine an STP/RSTP/MSTP snoop. For example: Port 1,
port 2 and port 3 combine an STP snoop. See Figure 3-23.
Step 5 Click Save.
The states of port 1, port 2 and port 3 will change.
Figure 3-22 MSTP
Figure 3-23 STP snoop
Advanced Settings 27