Edge-Core ES3510MA, Management Manual

Page: 774 / 984

C
HAPTER
33
| Spanning Tree Commands
– 774 –
spanning-tree mst
cost
This command configures the path cost on a spanning instance in the
Multiple Spanning Tree. Use the no form to restore the default auto-
configuration mode.
S
YNTAX
spanning-tree mst instance-id cost cost
no spanning-tree mst instance-id cost
instance-id - Instance identifier of the spanning tree.
(Range: 0-4094, no leading zeroes)
cost - Path cost for an interface. (Range: 0 for auto-configuration,
1-65535 for short path cost method
13
, 1-200,000,000 for long path
cost method)
The recommended path cost range is listed in
Table 100 on
page 769 . The recommended path cost is listed in Table 101 on
page 769 .
D
EFAULT
S
ETTING
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. The default path costs are listed in Table 102 on page 770 .
C
OMMAND
M
ODE
Interface Configuration (Ethernet, Port Channel)
C
OMMAND
U
SAGE
◆
Each spanning-tree instance is associated with a unique set of VLAN
IDs.
◆
This command is used by the multiple spanning-tree algorithm to
determine the best path between devices. Therefore, lower values
should be assigned to interfaces attached to faster media, and higher
values assigned to interfaces with slower media.
◆
Use the no spanning-tree mst cost command to specify auto-
configuration mode.
◆
Path cost takes precedence over interface priority.
E
XAMPLE
Console(config)#interface Ethernet 1/5
Console(config-if)#spanning-tree mst 1 cost 50
Console(config-if)#
R
ELATED
C
OMMANDS
spanning-tree mst port-priority (775)
13. Use the
spanning-tree pathcost method
command to set the path cost method.