Owner's Manual

Chapter 18. STP | 527
NETGEAR 8800 User Manual
Domain (STPD). Each STPD has its own root bridge and active path. After an STPD is
created, one or more VLANs can be assigned to it.
A physical port can belong to multiple STPDs. In addition, a VLAN can span multiple STPDs.
The key points to remember when configuring VLANs and STP are:
• Each VLAN forms an independent broadcast domain.
• STP blocks paths to create a loop-free environment.
• Within any given STPD, all VLANs belonging to it use the same spanning tree.
To create an STPD, use the following command:
create stpd <stpd_name>
To delete an STPD, use the following command:
delete stpd <stpd_name>
For detailed information about configuring STP and various STP parameters on the switch,
see
Configuring STP on the Switch on page 572.
The remainder of this section describes the following topics:
• Member VLANs on page 527
• STPD Modes on page 529
• Encapsulation Modes on page 530
• STP States on page 531
• Binding Ports on page 532
• Rapid Root Failover on page 534
• STPD BPDU Tunneling on page 535
• STP and Hitless Failover—Modular Switches Only on page 537
Member VLANs
When you add a VLAN to an STPD, that VLAN becomes a member of the STPD. The two
types of member VLANs in an STPD are:
• Carrier
• Protected
Carrier VLAN
A carrier VLAN defines the scope of the STPD, which includes the physical and logical ports
that belong to the STPD and if configured, the 802.1Q tag used to transport Multiple Instance
Spanning Tree Protocol (EMISTP) or Per VLAN Spanning Tree (PVST+) encapsulated bridge
protocol data units (BPDUs) (see
Encapsulation Modes on page 530 for more information
about encapsulating STP BPDUs). Only one carrier VLAN can exist in a given STPD,
although some of its ports can be outside the control of any STPD at the same time.