Korenix JetNet 5228G Series, User Manual

Page: 522 / 658

Command Line Interface
4-212
4
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 spanning-tree pathcost method (page 4-206) is set to short, the
maximum value for path cost is 65,535.
Example
Table 4-64 Recommended STA Path Cost
Port Type Link Type IEEE 802.1D-1998 IEEE 802.1w-2001
Ethernet Half Duplex
Full Duplex
Trunk 100
95
90 2,000,000
1,999,999
1,000,000
Fast Ethernet Half Duplex
Full Duplex
Trunk 19
18
15 200,000
100,000
50,000
Gigabit Ethernet Full Duplex
Trunk 4
3 10,000
5,000
Table 4-65 Default STA Path Costs
Port Type Link Type IEEE 802.1w-2001
Ethernet Half Duplex
Full Duplex
Trunk 2,000,000
1,000,000
500,000
Fast Ethernet Half Duplex
Full Duplex
Trunk 200,000
100,000
50,000
Gigabit Ethernet Full Duplex
Trunk 10,000
5,000
Console(config)#interface ethernet 1/5
Console(config-if)#spanning-tree cost 50
Console(config-if)#