C
HAPTER
 34
  |  Spanning Tree Commands
–  1079  –
RELATED COMMANDS
spanning-tree edge-port (1080)
spanning-tree spanning-disabled (1088)
spanning-tree cost This command configures the spanning tree path cost for the specified 
interface. Use the no form to restore the default auto-configuration mode.
SYNTAX 
spanning-tree cost cost
no spanning-tree cost
cost - The path cost for the port. (Range: 0 for auto-configuration, 
1-65535 for short path cost method
23
, 1-200,000,000 for long path 
cost method)
DEFAULT SETTING 
By default, the system automatically detects the speed and duplex mode 
used on each port, and configures the path cost according to the values 
shown below. Path cost “0” is used to indicate auto-configuration mode. 
When the short path cost method is selected and the default path cost 
recommended by the IEEE 8021w standard exceeds 65,535, the default is 
set to 65,535. 
COMMAND MODE 
Interface Configuration (Ethernet, Port Channel)
COMMAND USAGE 
◆ This command is used by the Spanning Tree Algorithm to determine the 
best path between devices. Therefore, lower values should be assigned 
to ports attached to faster media, and higher values assigned to ports 
with slower media. 
23. Use the spanning-tree pathcost method command on page 1071 to set the path cost 
method.
Table 126: Recommended STA Path Cost Range 
Port Type Short Path Cost 
(IEEE 802.1D-1998)
Long Path Cost 
(802.1D-2004)
Ethernet 50-600 200,000-20,000,000
Fast Ethernet  10-60 20,000-2,000,000
Gigabit Ethernet 3-10  2,000-200,000
Table 127: Default STA Path Costs 
Port Type Short Path Cost 
(IEEE 802.1D-1998)
Long Path Cost
(802.1D-2004)
Ethernet 65,535  1,000,000
Fast Ethernet  65,535  100,000
Gigabit Ethernet 10,000  10,000