Alcatel-Lucent OmniSwitch 6850-48 - Quick Steps for Configuring Mstis

Quick Steps for Configuring MSTIs Using 802.1Q 2005 Multiple Spanning Tree
page 12-16 OmniSwitch AOS Release 6 Network Configuration Guide September 2009
Quick Steps for Configuring MSTIs
By default, the Spanning Tree software is active on all switches and operating in the 1x1 mode using
802.1w RSTP. A loop-free network topology is automatically calculated based on default 802.1w RSTP
switch, bridge, and port parameter values.
Using Multiple Spanning Tree (MST) requires configuration changes to the default Spanning Tree values
(mode and protocol) as well as defining specific MSTP parameters and instances.
The following steps provide a tutorial for setting up a sample MSTP configuration, as shown in the
diagram below:
Flat Mode MSTP Quick Steps Example
1 Change the Spanning Tree operating mode, if necessary, on Switch A and Switch B from 1x1 to flat
mode using the bridge mode command. For example:
-> bridge mode flat
Note that defining an MSTP configuration requires the use of explicit Spanning Tree commands, which
are available in both the flat and 1x1 mode. As a result, this step is optional. See “Using Spanning Tree
Configuration Commands” on page 12-10 for more information.
2 Change the Spanning Tree protocol to MSTP using the bridge protocol command. For example:
-> bridge protocol mstp
3 Create VLANs 100, 200, 300, and 400 using the vlan command. For example:
-> vlan 100
-> vlan 150
-> vlan 200
-> vlan 250
4 Assign switch ports to VLANs, as shown in the above diagram, using the vlan port default command.
For example, the following commands assign ports 3/1, 4/2, 4/8, and 2/12 to VLANs 100, 150, 200, and
250 on Switch A:
-> vlan 100 port default 3/1
-> vlan 150 port default 4/2
-> vlan 200 port default 4/8
-> vlan 250 port default 2/12
2/1
3/1
4/2
4/8
5/2
5/1
||
VLAN 100
VLAN 250
MSTI-1
VLAN 200
VLAN 150
CIST-0
VLAN 100
VLAN 250
MSTI-1
VLAN 200
VLAN 150
CIST-0
||
2/12
3/6
||
Switch A Switch B