Allied Telesis AT-S60 - Manual (Page 203)

Chapter 12: STP, RSTP, and MSTP
Section II: Local and Telnet Management 202
to 240 in increments of 16. The default value is 8 (priority value
128). For a list of the increments, refer to Table 7, Port Priority
Value Increments on page 189.
2 - Port Cost
The spanning tree algorithm uses the cost parameter to decide
which port provides the lowest cost path to the root bridge for
that LAN. The range is 0 to 200,000,000. The default setting is
Auto-detect, which sets port cost depending on the speed of the
port. Default values are 2,000,000 for 10 Mbps ports, 200,000 for a
100 Mbps ports, and 20,000 for one gigabit ports.
6. After making changes, type R until you return to the Main Menu. Then
type S to select Save Configuration Changes.