Sample Spanning Tree Configuration; Example Network Overview - Alcatel-Lucent OmniSwitch 9900 Series Network Configuration Manual

Configuring Spanning Tree Parameters

Sample Spanning Tree Configuration

This section provides an example network configuration in which the Spanning Tree Algorithm and
Protocol has calculated a loop-free topology. In addition, a tutorial is also included that provides steps on
how to configure the example network topology using the Command Line Interface (CLI).
Note that the following example network configuration illustrates using switches operating in the per-
VLAN Spanning Tree mode and using RSTP (802.1w) to calculate a single data path between VLANs.
See "MST General Overview" on page 6-12

Example Network Overview

The following diagram shows a four-switch network configuration with an active Spanning Tree topology,
which was calculated based on both configured and default Spanning Tree parameter values:
VLAN 255 Bridge ID
10, 00:d0:95:00:00:01
VLAN 255 Bridge ID
32768, 00:d0:95:00:00:02
In the above example topology:
•
Each switch is operating in the per-VLAN Spanning Tree mode by default.
•
Each switch configuration has a VLAN 255 defined. The Spanning Tree administrative status for this
VLAN was enabled by default when the VLAN was created.
•
VLAN 255 on each switch is configured to use the 802.1w (rapid reconfiguration) Spanning Tree
Algorithm and Protocol.
•
Ports 2/1-3, 2/8-10, 3/1-3, and 3/8-10 provide connections to other switches and are all assigned to
VLAN 255 on their respective switches. The Spanning Tree administrative status for each port is
enabled by default.
OmniSwitch AOS Release 8 Network Configuration Guide
for an overview and examples of using MSTP (802.1s).
Switch D
(Root Bridge)
2/3
2/2
2/1
PC=4
2/10
2/8
2/9
Switch A
(Designated Bridge)
Forwarding
Blocking
Example Active Spanning Tree Topology
Sample Spanning Tree Configuration
Switch C
PC=4 3/8
PC=19 3/9
3/10
PC=19
3/2
PC=4 3/3
PC=4 3/1
Switch B
Root Port
Designated Port
Path Cost
December 2017
VLAN 255 Bridge ID
32768, 00:d0:95:00:00:04
VLAN 255 Bridge ID
32768, 00:d0:95:00:00:03
PC
page 6-43