Alcatel-Lucent 060321-10, Rev. B, Cli Reference Manual

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spantree cist path-cost Distributed Spanning Tree Commands
page 5-38 OmniSwitch CLI Reference Guide March 2011
spantree cist path-cost
Configures the Spanning Tree path cost value for a port or a link 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.
spantree cist {port slot/port[-port2] | linkagg linkagg_id[-linkagg_id2]} path-cost path_cost
Syntax Definitions
slot/port[-port2] The slot number and port number of the physical port. Use a hyphen to
specify a range of ports (4/1-8)
.
linkagg_id[-linkagg_id2] The link aggregate ID number. Use a hyphen to specify a range of IDs
(10-20).
path_cost Path cost value. The valid range is 0 - 65535 for 16-bit, 0–200000000
for 32-bit.
Defaults
By default, the path cost is set to zero.
Platforms Supported
OmniSwitch 10K
Usage Guidelines
•
This command only applies to the port path cost value for the CIST instance regardless of which oper-
ating mode (flat or per-VLAN) or protocol is active for the switch.
•
If the switch is running in per-VLAN 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 spantree 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.
•
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:
Link Speed
IEEE 802.1D
Recommended Value
10 MB 2,000,000
100 MB 200,000
1 GB 20,000
10 Gbps 2,000