Defining Mstp Properties; Multiple Spanning Tree - Cisco SF 300-08 Administration Manual

Configuring the Spanning Tree Protocol

Defining MSTP Properties

Defining MSTP Properties
STEP 1
STEP 2
Cisco Small Business 300 Series Managed Switch Administration Guide
3. Associate these MTP instances to VLAN(s), deciding which MSTP instance will
be active in what VLAN.
4. Configure the MSTP attributes by:
• Defining MSTP Properties
• Defining MST Instance Settings
• Mapping VLANs to a MST Instance
• Defining MSTP Interface Settings
The global Multiple Spanning Tree Protocol (MSTP) configures a separate
Spanning Tree for each VLAN group and blocks all but one of the possible
alternate paths within each Spanning Tree. MSTP allows formation of MST regions
that can run multiple MST instances (MSTI). Multiple regions and other STP
bridges are interconnected using one single common spanning tree (CST).
MSTP is fully compatible with RSTP bridges, in that an MSTP BPDU can be
interpreted by an RSTP bridge as an RSTP BPDU. This not only allows
compatibility with RSTP bridges without configuration changes, but also causes
any RSTP bridges outside of an MSTP region to see the region as a single RSTP
bridge, regardless of the number of MSTP bridges inside the region itself.
For two or more switches to be in the same MST region, they must have the same
VLANs to MST instance mapping, the same configuration revision number, and the
same region name.
Switches intended to be in the same MST region are never separated by switches
from another MST region. If they are separated, the region become two separate
regions.
This mapping can be done in the VLAN to MST Instance Page.
Configuration on this page applies if the system STP mode is MSTP.
To define MSTP:
Click Spanning Tree > STP Status and Global Settings. The
Global Settings Page
Click Spanning Tree > MSTP Properties. The
displays. Enable MSTP.
STP Status and
MSTP Properties Page
12
displays.
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