Configuring port priority and port path cost, Configuring bridge priority for an mstp instance, Setting the mstp global parameters – Brocade BigIron RX Series Configuration Guide User Manual
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BigIron RX Series Configuration Guide
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802.1s Multiple Spanning Tree Protocol
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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 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.
BigIron RX(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 switch. 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.
BigIron RX(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 switch. 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.
Setting the MSTP global parameters
MSTP has many of the options available in RSTP as well as some unique options. To configure
MSTP Global parameters for all instances on a switch.
BigIron RX(config)# mstp force-version 0 forward-delay 10 hello-time 4 max-age 12
max-hops 9