mstp instance
mstp instancenumber{prioritypriority-num|vlanvlan-id[tovlan-id]|vlan-groupgroup-id|laglag-id|ethernetunit/slot/port [tounit/slot/port]{path-costcost-value[prioritypriority-value] |
prioritypriority-value[path-costcost-value]}}no mstp instancenumber{prioritypriority-num|vlanvlan-id[tovlan-id]|vlan-groupgroup-id|laglag-id|ethernetunit/slot/port[tounit/slot/port]{path-costcost-value[prioritypriority-value] |
prioritypriority-value[path-costcost-value]}}No MSTP instances are configured; any VLANs remain in the Common and Internal Spanning Tree (CIST) or stay free.
- number
- Specifies the number for the instance of MSTP that you are configuring. You can specify up to 15 instances, identifying each, in MSTP mode, by a number in the range from 1 through 4094. In MSTP mode, you cannot specify the value 0, which identifies the CIST. In MSTP+ mode, the range is from 0 through 4094.
- prioritypriority-num
- Configures the priority for an MSTP instance. Valid values are from 0 through 61440 in increments of 4096. The default value is 128.
Global configuration mode
Use of the
mstp instance allows you to use fewer spanning-tree instances to map to VLANs.
The RUCKUS implementation of MSTP allows you to assign VLANs or ranges of VLANs to an MSTP instance before or after they have been defined. If predefined, a VLAN is placed in the Multiple Spanning Tree Protocol Instance (MSTI) that it was assigned to immediately upon the creation of the VLAN. Otherwise, the default operation is to assign all new VLANs to the CIST. VLANs assigned to the CIST by default can be moved later to a specified MSTI.
The system does not allow an MSTI without any VLANs mapped to it. Removing all VLANs from an MSTI deletes the MSTI from the system. By contrast, the CIST exists regardless of whether any VLANs are assigned to it. Consequently, if all VLANs are removed from the CIST, the CIST continues to exist and remains functional.
You can set a priority to the instance, giving it a 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.
The system does not allow an MSTP instance without any VLANs mapped to it; removing all VLANs from an MSTP instance deletes the instance from the system.
In MSTP+ mode, you can specify an instance number value of 0 because MSTP+ mode allows you to add VLANs to and remove VLANs from the CIST.
The no form of the command in MSTP mode moves a VLAN or VLAN group from its assigned MSTP into the CIST.
The no form of the command in MSTP+ mode assigns any VLAN as a free VLAN.
The following example configures an MSTP instance and map VLANs 1 to 7 to it.
device(config)# mstp instance 7 vlan 4 to 7
The following example specifies a priority of 8192 to MSTP instance 1.
device(config)# mstp instance 1 priority 8192
The following example configures a path cost of 20000 to MSTP ports.
device(config)# mstp instance 1 ethernet 1/1/4 ethernet 1/1/5 ethernet 1/1/15 to 1/1/17 pathcost 20000
The following example configures a priority of 192 to the MSTP ports.
device(config)# mstp instance 1 ethernet 1/1/4 ethernet 1/1/5 ethernet 1/1/15 to 1/1/17 priority 192
| Release version | Command history |
|---|---|
| 08.0.61 | This command was modified to include LAG ID options. |
| 08.0.90 | This command was modified to configure the range for path cost and priority. |