Configuring Multiple Spanning Tree Protocol (MSTP)

Multiple Spanning Tree Protocol (MSTP) is used to create a loop-free topology in networks using multiple spanning-tree regions in which each region contains multiple spanning-tree instances (MSTIs). MSTIs provide different paths for different VLANs. 

Here is a guide on configuring AMG510 & AMG570 switches with MSTP: 

Step 1: On your left-hand side of the Web GUI, navigate to Configuration > System > IP

Step 2: Below the IP Interfaces section, select ‘Add interface’ and specify your VLAN as well as the IP Address and subnet mask within that VLAN and press save. In the example below you can see that the IP Address in VLAN 10 for this switch is 192.168.10.1 with a subnet mask of 24

Step 3: On the left hand-side of the Web GUI, Navigate to Configuration > VLANs

Step 4: To configure access across multiple VLANs on this switch, you must specify which VLANs to provide access to. In the example below, you can see that there is access to 3 VLANs which are VLAN 1, VLAN 10 and VLAN 20. Once you have input the VLANs you would like to provide access to, press ‘save’

Step 5: On the left-hand side of the Web GUI, Navigate to Configuration > Spanning tree > Bridge Settings 

Step 6: On the Basic settings, select the ‘Protocol Version’ drop down and press ‘MSTP’. If this switch is your Root switch, you can specify the bridge priority to a lower value. Once you have done this, press 'save'

Step 7: On the left-hand side of the Web GUI, Navigate to Configuration > Spanning tree > MSTI Mapping

Step 8: To create Multiple Spanning Tree instances, input which VLANs you would like to map to which MSTI group and press ‘save’. In the example below you can see ‘MSTI1’ has ‘VLAN 10’ mapped to it and ‘MSTI2’ has ‘VLAN 20’ mapped to it

Note: You can have multiple VLANs mapped to a singular MSTI 

Step 9: On the left-hand side of the Web GUI, select Configuration > Spanning Tree > MSTI Priorities 

Step 10: Specify the priority for your MSTIs as well as the CIST and press ‘save' 

Step 11: On the left-hand side of the Web GUI, select Configuration > Spanning Tree > CIST Ports 

Step 12: On the ‘CIST Normal Port Configuration’, change the ‘Admin Edge’ on each port in use from ‘Non-Edge' to ‘Edge’ and select ‘save’

Step 13: To verify your configuration, on the left-hand side of the Web GUI, select Monitory > Spanning Tree > Bridge Status 

Step 14: Your Multiple Spanning Tree instances (MSTIs) will show in the table below ‘STP Bridges’. Verify that the MSTIs have the correct Root switch with Priority value [PriorityValue.MAC-Address]. In the example below you can see this as ‘16385.54-51-46-F0-1F-76' for ‘MSTI1’

Step 1: Log in to the switch via SSH or Console

Step 2: Enter configuration mode by using the “configure terminal” command 

configure terminal

Step 3: Enable access to VLANs on your network by typing in the command “vlan [VLAN Number]” and pressing enter. (You can add VLANs separated by spaces or a comma) 

vlan [VLAN NUMBER]

Step 4: Configure a VLAN with an IP address by entering the command “interface vlan [VLAN Number]”, this command will take you into the configuration mode of that specific VLAN interface. To set your IP address for this VLAN, enter the command “ip address [IP address_Subnet mask]”. Once you have done this, type in “exit” and press enter to return to configuration mode 

interface vlan [VLAN Number]

ip address [IP Address_Subnet mask]

exit

Step 5: Use the following command to specify your spanning tree mode “spanning tree mode mstp”. Once you have entered this command, you must specify your bridge priority value in increments of ‘4096’, For example, “spanning tree mst 0 priority [Priority Value]”

spanning tree mode mstp

spanning tree mst 0 priority [Priority Value]

Step 6: To create your Multiple Spanning Tree instances and map them to a specific VLAN, you must enter the command “spanning-tree mst [MST group number] vlan [VLAN Number]”. Exit the configuration mode by typing “exit”

spanning-tree mst [MST Group number] vlan [VLAN Number]

exit

Step 7: To verify your configuration, enter the command “show spanning-tree mst” or “show spanning-tree active”

show spanning-tree mst

show spanning-tree active

Step 8: Save your configuration by entering the command “copy running-config startup-config"

copy running-config startup-config

CLI MSTP configuration example: