Alteon Application Switch Operating System Application Guide
Spanning Tree Protocol
Document ID: RDWR-ALOS-V2900_AG1302
107
Example
RSTP Configuration
1. Create VLAN and add ports.
Once ports have been readied for VLAN membership, VLAN 3 can be created and the ports
added to the VLAN.
2. Disable and clear STP groups 2 through 32.
3. Set the spanning tree mode to rapid spanning tree.
4. Configure STP Group 1 parameters.
Multiple Spanning Tree Protocol
IEEE 802.1s Multiple Spanning Tree Protocol (MSTP) extends the IEEE 802.1w RSTP through
multiple STGs. MSTP maintains up to 16 spanning-tree instances that correspond to STP Groups 1
through 16.
In MSTP, several VLANs can be mapped to each spanning tree instance. Each spanning tree instance
is independent of other instances. MSTP allows frames assigned to different VLANs to follow
separate paths, each path based on an independent spanning tree instance. This approach provides
multiple forwarding paths for data traffic, enabling load balancing, and reducing the number of
spanning tree instances required to support a large number of VLANs.
By default, the spanning tree on the management ports is turned off in both STP/PVST+ mode and
in MSTP/RSTP mode.
>> Main# /cfg/l2/vlan 2
<If the VLAN was not already created, it would be created with this command.>
>> VLAN 2# add 2
>> VLAN 2# add 3
>> VLAN 2# add 4
>> Main# /cfg/l2/stg 2
(Select STP Group 2)
>> Spanning Tree Group 2# clear
(Clear STP Group 2 parameters)
>> Spanning Tree Group 2# off
(Turn off STP Group 2)
>> Main# /cfg/l2/mrst
(Select Multiple Spanning Tree menu)
>> Multiple Spanning Tree# mode rstp
(Set mode to Rapid Spanning Tree)
>> Multiple Spanning Tree# on
(Turn Rapid Spanning Tree on)
>> /cfg/l2/stg 1
(Select Spanning Tree Protocol menu)
>> Spanning Tree Group 1# add 2
(Add VLAN 2 to STP Group 1)
>> Spanning Tree Group 1# apply
(Apply the configurations)
>> Spanning Tree Group 1# save
(Save the configuration)
