Quick Reference Guide

PowerConnect B-Series TI24X Configuration Guide 165
53-1002269-02
802.1s Multiple Spanning Tree Protocol
6
To configure an MSTP revision number, use a command such as the following at the Global
Configuration level.
PowerConnect(config)#mstp revision 4
Syntax: [no] mstp revision <revision-number>
The revision parameter specifies the revision level for MSTP that you are configuring on the switch.
It can be a number from 0 and 65535. The default revision number is 0.
Configuring an MSTP instance
An MSTP instance is configured with an MSTP ID for each region. Each region can contain one or
more VLANs. The Dell implementation of MSTP allows you to assign VLANS or ranges of VLANs to
an MSTP instance before or after they have been defined. If pre-defined, a VLAN will be placed in
the MSTI that it was assigned to immediately when the VLAN is created. Otherwise, the default
operation is to condition of assign all new VLANs to the CIST. VLANs assigned to the CIST by default
can be moved later to a specified MSTI.
To configure an MSTP instance and map one or more VLANs to that MSTI, use a command such as
the following at the Global Configuration level.
PowerConnect(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
value 0 (which identifies the CIST) cannot be used. You can have up to 15 instances, number 1 –
4094.
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.
The no option moves a VLAN or VLAN group from its assigned MSTI back into the CIST.
NOTE
The system does not allow an MSTI without any VLANs mapped to it. Consequently, removing all
VLANs from an MSTI, deletes the MSTI from the system. The CIST by contrast will exist regardless of
whether or not any VLANs are assigned to it or not. Consequently, if all VLANs are moved out of a
CIST, the CIST will still exist and functional.
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.
PowerConnect(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.