Command Line Interface Reference Guide > The Configuration Menu > /cfg/l2/stg Spanning Tree Group Configuration
/cfg/l2/stg
Spanning Tree Group Configuration
When multiple paths exist on a network, the Spanning Tree Protocol (STP) configures the network so that an Alteon uses only the most efficient path. STP detects and eliminates logical loops in a bridged or switched network. STP forces redundant data paths into a standby (blocked) state. When multiple paths exist, STP configures the network so that an Alteon uses only the most efficient path. If that path fails, STP automatically sets up another active path on the network to sustain network operations. As a result, STP is used to prevent loops in the network topology.
Alteon supports the IEEE 802.1p Spanning Tree Protocol (STP), and supports up to 16 instances of spanning trees or spanning tree groups. Each VLAN can be placed in only one spanning tree group per Alteon, except for the default spanning tree group (STG 1). The default group can have more than one VLAN. All other spanning tree groups (2 through 16) can have only one VLAN associated with them.
STP can be enabled or disabled for each port. Multiple spanning trees can be enabled on tagged or untagged ports. For a detailed description of this feature, see the Alteon Command Line Interface Application Guide.
 
[Spanning Tree Group 1 Menu]
brg - Bridge parameter menu
port - Port parameter menu
add - Add VLAN(s) to Spanning Tree Group
remove - Remove VLAN(s) from Spanning Tree Group
clear - Remove all VLANs from Spanning Tree Group
on - Globally turn Spanning Tree ON
off - Globally turn Spanning Tree OFF
default - Default Spanning Tree and Member parameters
untgpvst- Enable/Disable sending PVST frames on untagged ports
cur - Display current bridge parameters
Note: When VRRP is used for active-active redundancy, STP must be enabled.
 
Spanning Tree Configuration Menu (/cfg/l2/stg) 
Command Syntax and Usage
brg
 
Displays the Bridge Spanning Tree menu. To view this menu, see /cfg/l2/stg/brg Bridge Spanning Tree Configuration.
port <port number>
 
Displays the Spanning Tree Port menu. To view this menu, see /cfg/l2/stg <STG Group Index> /port <port #> Spanning Tree Port Configuration.
add <VLAN numbers or range (1-4090)>
 
Associates a VLAN or range of VLANs with a spanning tree and requires an external VLAN ID as a parameter.
remove <VLAN numbers or range, 1-4095 (802.1d & RSTP) / 2-4094 (MSTP)>
 
Breaks the association between a VLAN or range of VLANs and a spanning tree and requires an external VLAN ID as a parameter.
clear
 
Removes all VLANs from a spanning tree.
on
 
Globally enables STP. STP is turned on by default.
off
 
Globally disables STP.
default
 
Resets the STG and group member parameters to the factory default.
untgpvst
 
Specifies whether Alteon sends Cisco Per VLAN Spanning Tree (PVST+) protocol frames on untagged ports.
Notes:
*Alteon supports PVST and RPVST only when a spanning tree group STG group other than 1 is configured.
*Enable this option to forward BPDUs on untagged ports
Default: disable
cur
 
Displays the current STP parameters.