STG

The BayStack 470 Switch supports a single STG in one standalone switch. When working with a STG, observe the following rules:

In the configuration of the BayStack 470 Switch, a single STG with the ID of 1 includes all ports on the switch.

The Default STG sends only untagged BPDUs in order to operate with all devices that support only one instance of STP.

Although ports can be added to or deleted from the Default STG, the Default STG itself cannot be deleted from the system.

The ports associated with a VLAN and VLANs themselves must be contained within a single STG.
When a VLAN spans multiple switches, the VLAN must be within the same spanning tree group (have the STG ID) across all the switches.
When a VLAN is assigned to the STG, all ports belonging to that VLAN automatically join the STG. And, all VLANs in the same shared database (SVL) must be assigned to the STG.
All members of a particular MultiLink Trunking (MLT) group must be assigned to the STG.
Tagged ports can belong to more than one STG, but untagged ports can belong to the STG.

Because some STP-compliant devices do not support tagging, you can configure whether to send tagged or untagged BPDUs, even from tagged ports, with the BayStack 470 Switch with software version 1.2. The VLAN ID for the tagged BPDUs will be 4000+STG ID.

Note: You cannot remove VLAN 1 from the spanning tree group (STG) 1.

See also