TP-Link T1600G-18TS Configuration Manual page 270

Configuring Spanning Tree Configuration Example for MSTP
Figure 5-5 Configuring the VLAN-Instance Mapping
4) Choose the menu Spanning Tree > MSTP Instance > Instance Port Config to load the
following page. Set the path cost of port 1/0/1 in instance 1 as 400000.
Configuration Guide 247