Brocade Multi-Service IronWare Switching Configuration Guide (Supporting R05.6.00) - Manual (Page 388)

358 Multi-Service IronWare Switching Configuration Guide
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802.1s Multiple Spanning Tree Protocol
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Configuring an MSTP instance
An MSTP instance is configured with an MSTP ID for each region. Each region can contain one or
more VLANs. To configure an MSTP instance and assign a range of VLANs, use a command such as
the following at the Global Configuration level.
Brocade(config) # mstp instance 7 vlan 4 to 7
Syntax: [no] mstp instance instance-number [ vlan vlan-id | vlan-group group-id ]
The instance parameter defines the number for the instance of MSTP that you are configuring. The
maximum number of instances that can be configured is 16.
The vlan parameter assigns one or more VLANs or a range of VLANs to the instance defined in this
command.
The vlan-group parameter assigns one or more VLAN groups to the instance defined in this
command.
Configuring port priority and port path cost
Priority and path cost can be configured for a specified instance. To configure an MSTP instance,
use a command such as the following at the Global Configuration level.
Brocade(config)# mstp instance 7 ethernet 3/1 priority 32 path-cost 200
Syntax: [no] mstp instance instance-number ethernet slot/port priority port-priority path-cost
cost
The instance-number variable is the number of the instance of MSTP that you are configuring
priority and path cost for.
The ethernet slot/port parameter specifies a port within a VLAN. The priority and path cost
configured with this command will apply to VLAN that the port is contained within.
You can set a priority to the port that gives it forwarding preference over lower priority instances
within a VLAN or on the device. A higher number for the priority variable means a lower forwarding
priority. Acceptable values are 0 - 240 in increments of 16. The default value is 128.
A path-cost can be assigned to a port to bias traffic towards or away from a path during periods of
rerouting. Possible values are 1 - 200000000.
Configuring bridge priority for an MSTP instance
Priority can be configured for a specified instance. To configure priority for an MSTP instance, use a
command such as the following at the Global Configuration level.
Brocade(config)# mstp instance 1 priority 8192
Syntax: [no] mstp instance instance-number priority priority-value
The instance-number variable is the number for the instance of MSTP that you are configuring.
You can set a priority to the instance that gives it forwarding preference over lower priority
instances within a VLAN or on the device. A higher number for the priority variable means a lower
forwarding priority. Acceptable values are 0 - 61440 in increments of 4096. The default value is
32768.