Spanning-Tree Operation 
802.1s Multiple Spanning Tree Protocol (MSTP) 
Note on MSTP Rapid 
State Transitions 
Note 
Under some circumstances the rapid state transitions employed by MSTP (and 
RSTP) can increase the rates of frame duplication and misordering in the 
switched LAN. To allow MSTP switches to support applications and protocols 
that may be sensitive to frame duplication and misordering, setting the Force 
Protocol Version (force-version) parameter to stp-compatible allows MSTP to 
operate with rapid transitions disabled. The value of this parameter applies to 
all ports on the switch. See the information on force-version on page
 6-60. 
Steps for Configuring MSTP 
This section outlines the general steps for configuring MSTP operation in your 
network, and assumes you have already planned and configured the VLANs 
you want MSTP to use. The actual MSTP parameter descriptions are in the 
following sections. 
The switch supports MSTP configuration through the CLI. After you specify 
MSTP and reboot the switch as described above, the switch removes the 
Spanning Tree option from the Menu interface. If you later reconfigure the 
switch to use STP or RSTP, the switch returns the Spanning Tree option to the 
Menu interface. 
This section assumes that you have already 
1.  Configured the MSTP operation mode. This specifies MSTP as the span-
ning tree operating mode. Changing the current MSTP operation mode 
requires you to save the change and reboot to activate the selection. 
spanning-tree protocol-version < stp | rstp | mstp > 
2.  Configure MSTP global parameters. This step involves configuring the 
following: 
•  Required parameters for MST region identity: 
Region Name: spanning-tree config-name 
Region Revision Number: spanning-tree config revision 
•  Optional MSTP parameter changes for region settings: 
HP recommends that you leave these parameters at their default 
settings for most networks. Refer to the “Caution” on page 6-47. 
–  The maximum number of hops before the MSTP BPDU is dis-
carded (default: 20) 
spanning-tree max-hops 
6-55