Configuration: Spanning Tree
Overview
This section provides information for Spanning Tree in Configuration.
The Switch supports Spanning Tree Protocol (STP), Rapid Spanning Tree Protocol (RSTP) and Multiple Spanning Tree Protocol (MSTP) as defined in the following standards.
• IEEE 802.1D Spanning Tree Protocol
• IEEE 802.1w Rapid Spanning Tree Protocol
• IEEE 802.1s Multiple Spanning Tree Protocol
Spanning Tree
(R)STP detects and breaks network loops and provides backup links between switches, bridges or routers. It allows a switch to interact with other (R)STP-compliant switches in your network to ensure that only one path exists between any two stations on the network.
Global Settings
Use this screen to view the Global settings. Click Configuration > Spanning Tree.
The following table describes the labels in this screen.
Label | Description |
|---|---|
Global | |
State | Select to Enable or Disable the Spanning-Tree function. |
BPDU Forward | Select the bridge protocol data units forward (BPDU) option to be Flooding or Filtering. |
Path Cost Method | Select Short or Long as a Path Cost method. Path cost is the cost of transmitting a frame on to a LAN through that port. It is recommended that you assign this value according to the speed of the bridge. The slower the media, the higher the cost. |
Version | Select the type of spanning tree protocol to use. The following options are available: • Select STP for a small home or office network with only a few switches involved. • Select RSTP for a medium-sized business network with multiple switches involved. • Select MSTP for an enterprise network with VLANs and complex topologies. |
Configuration Name | Enter the name of the configuration in hexadecimal. The maximum number characters is 32. |
Configuration Revision | Enter the revision number of configuration. The number can be between 0 and 65535. |
Apply | Click Apply to save the changes. |
Cancel | Click Cancel to discard the changes. |
STP Port
Use this screen to view the STP Port settings. Click Configuration > Spanning Tree > STP Port.
The following table describes the labels in this screen.
Label | Description |
|---|---|
STP Port | |
Port | Displays the index number of the STP port. |
State | Display the status of the STP port as enabled or disabled. |
External Cost | Displays the external path cost. |
Edge Port | Displays the edge port status as Yes or No. |
BPDU Filter | Displays the BPDU filter status as Yes or No. |
P2P MAC | Displays the P2P MAC status as Yes or No. |
Edit | Select this checkbox to configure the properties of a port. Click the Edit button change the properties of the port. |
Cancel | Click Cancel to discard the changes. |
STP Port Edit
Use this screen to configure the STP Port Edit settings. Click Configuration > Spanning Tree > STP Port > Edit.
The following table describes the labels in this screen.
Label | Description |
|---|---|
STP Port | |
Port List | Enter the index number of the STP ports. |
External Path Cost (0=Auto) | Enter the external path cost. Enter 0 for Auto. |
State | Select the state of the STP port as enabled or disabled. |
Edge Port | Select this checkbox to configure a port as an edge port when it is directly attached to a computer. An edge port changes its initial STP port state from blocking state to forwarding state immediately without going through listening and learning states right after the port is configured as an edge port or when its link status changes.  An edge port becomes a non-edge port as soon as it receives a Bridge Protocol Data Unit (BPDU). |
BPDU Filter | Select Yes to activate BPDU filter or No to deactivate it. |
P2P MAC | Select Yes to activate P2P MAC or No to deactivate it. |
Migrate | Select Yes to activate Migrate or No to deactivate it. |
Apply | Click Apply to save the changes. |
Cancel | Click Cancel to discard the changes. |
CIST Settings
Use this screen to view the CIST settings. Click Configuration > Spanning Tree > CIST.
The following table describes the labels in this screen.
Label | Description |
|---|---|
CIST Instance | |
Priority | Configure priority of CIST bridge ID. Priority is part of bridge ID, used for CIST root bridge selection. |
Max Hops | Enter a maximum number of hops value. The value can be between 1 and 40. |
Forward Delay | This is the maximum time (in seconds) a switch will wait before changing states. This delay is required because every switch must receive information about topology changes before it starts to forward frames. In addition, each port needs time to listen for conflicting information that would make it return to a blocking state; otherwise, temporary data loops might result. The allowed range is 4 to 30 seconds. As a general rule: 2 * (Forward Delay - 1) >= Max Age >= 2 * (Hello Time + 1) |
Max Age | This is the maximum time (in seconds) a switch can wait without receiving a BPDU before attempting to reconfigure. All switch ports (except for designated ports) should receive BPDUs at regular intervals. Any port that ages out STP information (provided in the last BPDU) becomes the designated port for the attached LAN. If it is a root port, a new root port is selected from among the switch ports attached to the network. The allowed range is 6 to 40 seconds. |
Tx Hold Count | Enter a transmission hold count value. The value can be between 1 and 10. |
Hello Time | This is the time interval in seconds between BPDU (Bridge Protocol Data Units) configuration message generations by the root switch. The allowed range is 1 to 10 seconds. |
Apply | Click Apply to save the changes. |
Cancel | Click Cancel to discard the changes. |
CIST Port
Use this screen to view the CIST Port settings. Click Configuration > Spanning Tree > CIST Port.
The following table describes the labels in this screen.
Label | Description |
|---|---|
CIST Port | |
Port | Displays the index number of the STP port. |
Priority | Displays the priority for each port here. |
External Path Cost | Displays the external path cost. |
Internal Path Cost | Displays the internal path cost. |
Edit | Select this checkbox to configure the properties of a port. Click the Edit button change the properties of the port. |
Cancel | Click Cancel to discard the changes. |
CIST Port Edit
Use this screen to configure the CIST Port Edit settings. Click Configuration > Spanning Tree > CIST Port > Edit.
The following table describes the labels in this screen.
Label | Description |
|---|---|
STP CIST Port | |
Port List | Enter the index number of the STP ports. |
Priority | Configure the priority for each port here. Priority decides which port should be disabled when more than one port forms a loop in a switch. Ports with a higher priority numeric value are disabled first. The allowed range is between 0 and 255 and the default value is 128. |
Internal Path Cost (0=Auto) | Enter the internal path cost. Enter 0 or Auto. |
Apply | Click Apply to save the changes. |
Cancel | Click Cancel to discard the changes. |
MST Settings
Use this screen to view the MST settings. Click Configuration > Spanning Tree > MST.
The following table describes the labels in this screen.
Label | Description |
|---|---|
MST Instance | |
MSTI | This displays the Multiple Spanning Tree Instances (MSTI). |
VLAN List | This displays a list of MSTI VLANs. |
VLAN Count | This displays the VLAN count. |
Priority | This displays the priority for each port here. |
Action | |
Edit | Click Edit to make changes to the entry. |
Delete | Click Delete to remove the entry. |
Add | Click Add to create a new MST Instance entry. |
Add or Edit MST
Use this screen to configure the MST settings. Click Configuration > Spanning Tree > MST > Add or Edit.
The following table describes the labels in this screen.
Label | Description |
|---|---|
MST Instance | |
MST ID | Select a Multiple Spanning Tree Instance (MSTI) ID. |
VLAN List | Enter a MSTI VLAN ID |
Priority | Select a MSTI bridge ID priority value. |
Apply | Click Apply to save the changes. |
Cancel | Click Cancel to discard the changes. |
MST Port Settings
Use this screen to view the MST Port settings. Click Configuration > Spanning Tree > MST Port.
The following table describes the labels in this screen.
Label | Description |
|---|---|
MST Port | |
MST ID | Select the MST port ID number from the dropdown list. |
Port | This displays the index number of the MST port. |
MSTI ID | This displays the index value of the MSTI. |
Priority | This displays the priority for each port. |
Internal Path Cost | This displays the internal path cost. |
Edit | Select this checkbox to configure the properties of a port. Click the Edit button change the properties of the port. |
Cancel | Click Cancel to discard the changes. |
MST Port Edit
Use this screen to configure the MST Port Edit settings. Click Configuration > Spanning Tree > MST Port > Edit.
The following table describes the labels in this screen.
Label | Description |
|---|---|
STP MST Port | |
MST ID | This displays the MST ID number. |
Port List | Enter the index number of the MTP ports. |
Priority | Configure the priority for each port here. Priority decides which port should be disabled when more than one port forms a loop in a switch. Ports with a higher priority numeric value are disabled first. The allowed range is between 0 and 255 and the default value is 128. |
Internal Path Cost (0=Auto) | Enter the internal path cost. Enter 0 for Auto. |
Apply | Click Apply to save the changes. |
Cancel | Click Cancel to discard the changes. |