N o t e o n M S T P R a p i d S t a t e Tr a n s i t i o n s

Multiple Instance Spanning-Tree Operation

802.1s Multiple Spanning Tree Protocol (MSTP)

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-compatibleallows MSTP to operate with rapid transitions disabled. The value of this parameter applies to all ports on the switch. See the information on force-versionon page 21.

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.

This section assumes that you have already:

1.Configured MSTP global parameters. This step involves configuring the following:

• Required parameters for MST region identity:

Region Name: spanning-tree config-nameRegion Revision Number: spanning-tree config revision

Optional MSTP parameter changes for region settings:

ProCurve recommends that you leave these parameters at their default settings for most networks. Refer to the “Caution” on page 9.

The maximum number of hops before the MSTP BPDU is dis- carded (default: 20)

spanning-tree max-hops

Force-Version operation

spanning-tree force-version

Forward Delay

spanning-tree forward-delay

Hello Time (used if the switch operates as the root device.) spanning-treehello-time

Maximum age to allow for STP packets before discarding spanning-treemaximum-age

5-17