Configuring Spanning Tree Protocol; Spanning Tree Switch Configuration - Ubiquiti EdgeSwitch ES-24-250W Administration Manual

EdgeSwitch Administration Guide
™

Configuring Spanning Tree Protocol

The Spanning Tree Protocol (STP) provides a tree topology for any arrangement of bridges. STP also provides
one path between end stations on a network, eliminating loops. Spanning tree versions supported include
Common STP, Multiple STP, and Rapid STP.
Classic STP provides a single path between end stations, avoiding and eliminating loops. For information on
configuring Common STP, see "Spanning Tree CST Port Configuration" on page 164.
Multiple Spanning Tree Protocol (MSTP) supports multiple spanning tree instances to efficiently channel
VLAN traffic over different interfaces. Each spanning tree instance behaves in the manner specified in IEEE
802.1w, Rapid Spanning Tree Protocol (RSTP), with slight modifications in the working but not the end effects
(a primary effect being the rapid transitioning of the port to 'Forwarding'). The difference between RSTP and
the traditional STP (IEEE 802.1D) is the ability to configure and recognize full-duplex connectivity and ports
which are connected to end stations, resulting in rapid transitioning of the port to 'Forwarding' state and
the suppression of Topology Change Notifications (TCNs). These features are represented by the parameters
'pointtopoint' and 'edgeport' . MSTP is compatible with both RSTP and STP. It behaves appropriately to STP
and RSTP bridges. A MSTP bridge can be configured to behave entirely as a RSTP bridge or a STP bridge.
Note: For two bridges to be in the same region, the force version should be 802.1S and their
configuration name, digest key, and revision level should match. For more information about regions
and their effect on network topology, refer to the IEEE 802.1Q standard.

Spanning Tree Switch Configuration

The Spanning Tree Switch Configuration page contains fields for enabling STP on the switch.
To display the Spanning Tree Switch Configuration page, click Switching > Spanning Tree > Switch in the
navigation menu.
Field
Spanning Tree Admin Mode
Force Protocol Version
Ubiquiti Networks, Inc.
Spanning Tree Switch Configuration
Spanning Tree Switch Configuration Fields
Description
The STP administrative mode. If set to Enable, the switch participates in the root bridge election
process and exchanges Bridge Protocol Data Units (BPDUs) with other switches in the spanning tree to
determine the root path costs and maintain topology information.
The STP version the device uses, which is one of the following:
• IEEE 802.1d Classic STP: Provides a single path between end stations, avoiding and eliminating loops.
• IEEE 802.1w Rapid Spanning Tree Protocol (RSTP): Can configure and recognize full-duplex
connectivity and ports connected to end stations, for rapid transitioning of port to Forwarding state
and suppression of TCNs.
• IEEE 802.1s Multiple Spanning Tree Protocol (MSTP): Supports multiple spanning tree instances
to efficiently channel VLAN traffic over different interfaces. Compatible with RSTP and STP.
Configuring Switching Information
161