Spanning-tree cost, Table 77, Table 78 – Brocade 6910 Ethernet Access Switch Configuration Guide (Supporting R2.2.0.0) User Manual
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Brocade 6910 Ethernet Access Switch Configuration Guide
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Spanning Tree Commands
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
7
, 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.
•
Path cost takes precedence over port priority.
•
When the path cost method (see
“spanning-tree pathcost method”
on page 334) is set to
short, the maximum value for path cost is 65,535.
Example
Console(config)#interface ethernet 1/5
Console(config-if)#spanning-tree cost 50
Console(config-if)#
TABLE 77
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
“spanning-tree pathcost method”
on page 334 to set the path cost method.
TABLE 78
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