Alcatel-Lucent OmniSwitch 6250, Cli Reference Manual, Page: 511 / 2018

Distributed Spanning Tree Commands
OmniSwitch 6250 CLI Reference Guide November 2009 page 16-71
bridge cist slot/port path cost
Configures the Spanning Tree path cost value for a port or an aggregate of ports for the flat mode
Common and Internal Spanning Tree (CIST) instance. This value is the contribution of this port to the
path cost towards the Spanning Tree root bridge that includes this port. Path cost is a measure of the
distance of the listed port from the root bridge in the number of hops.
bridge cist {slot/port | logical_port} path cost path_cost
Syntax Definitions
slot/port Enter the slot number for the module and the physical port number on
that module (e.g., 3/1 specifies port 1 on slot 3).
logical_port Link aggregate ID number (0–31).
path_cost Path cost value (0 - 65535 for 16-bit, 0–200000000 for 32-bit).
Defaults
By default, the path cost is set to zero.
Platforms Supported
OmniSwitch 6250
Usage Guidelines
•
This command is an explicit Spanning Tree command that only applies to the port path cost value for
the CIST instance regardless of which operating mode (flat or 1x1) or protocol is active on the switch.
•
If the switch is running in 1x1 mode when this command is used, the specified path cost value is not
active for the CIST instance until the operating mode for the switch is changed to the flat mode.
•
Note that when the Spanning Tree protocol is changed to/from MSTP, the bridge priority and port path
cost values for the flat mode CIST instance are reset to their default values.
•
Use the bridge path cost mode command to automatically select the path cost value based on the
active Spanning Tree protocol (16-bit for STP and RSTP, 32-bit for MSTP) or to use a 32-bit path cost
value regardless of which protocol is active.
•
Note that when a configuration snapshot is taken of the switch, all Spanning Tree commands are saved
in their explicit format.
•
If a 32-bit path cost value is in use and the path_cost is set to zero, the following recommended default
path cost values based on link speed are used: