Cisco Nexus 5000 Series Command Reference Release 4.0(1a)N2(1) (OL-16599-01, March 2009)

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Cisco Nexus 5000 Series Command Reference
OL-16599-01
Chapter 2 Ethernet Commands
spanning-tree mst root
spanning-tree mst root
To designate the primary and secondary root and set the timer value for an instance, use the
spanning-tree mst root command. To return to the default settings, use the no form of this command.
spanning-tree mst instance-id root {primary | secondary} [diameter dia [hello-time hello-time]]
no spanning-tree mst instance-id root
Syntax Description
Command Default None
Command Modes Configuration mode
Command History
Usage Guidelines You can enter the instance-id argument as a single instance or a range of instances, for example,
0-3,5,7-9.
If you do not specify the hello-time argument, the argument is calculated from the network diameter.
You must first specify the diameter dia keyword and argument before you can specify the hello-time
hello-time keyword and argument.
Examples This example shows how to designate the primary root:
switch(config)# spanning-tree mst 0 root primary
This example shows how to set the priority and timer values for the bridge:
switch(config)# spanning-tree mst 0 root primary diameter 7 hello-time 2
instance-id Instance identification number; the range of valid values is from 0 to 4094.
primary Specifies the high priority (low value) that is high enough to make the bridge
root of the spanning-tree instance.
secondary Specifies the switch as a secondary root, should the primary root fail.
diameter dia (Optional) Specifies the timer values for the bridge that are based on the
network diameter.
hello-time hello-time (Optional) Specifies the duration between the generation of configuration
messages by the root switch. The range is from 1 to 10 seconds; the default
is 2 seconds.
Release Modification
4.0(0)N1(1a) This command was introduced.