Reference Guide

N8406-022A 1Gb Intelligent L2 Switch Browser-based Interface Reference Guide 97
MSTP/RSTP General Configuration
To display the following form, select Layer 2 > MSTP/RSTP > General.
The switch supports the IEEE 802.1w Rapid Spanning Tree Protocol (RSTP) and IEEE 802.1s Multiple
Spanning Tree Protocol (MSTP). MSTP allows you to map many VLANs to a small number of spanning tree
groups, each with its own topology.
You can configure up to 31 spanning tree groups on this switch. MSTP/RSTP is turned off by default.
The following table describes the MSTP/RSTP General Configuration controls:
Table 79 MSTP/RSTP General Configuration controls
Control
Description
Region Name
Configures a name for the MSTP region. All devices within a MSTP region must
have the same region name.
The Region Name can have a maximum of 15 characters.
Revision Level (0-65535)
Configures a version number for the MSTP region. The version is used as a
numerical identifier for the region. All devices within a MSTP region must have
the same version number.
Max. Hop Count (4-60)
Configures the maximum number of bridge hops a packet may to traverse before
it is dropped. The range is from 4 to 60 hops. The default is 20.
MSTP/RSTP Mode
Selects either Rapid Spanning Tree Protocol (RSTP) or Multiple Spanning Tree
Protocol (MSTP).
The default mode is RSTP.
MSTP/RSTP State
Globally turns RSTP/MSTP on or off.
Note: When RSTP is turned on, the configuration parameters for STP group 1
apply to RSTP.
Default CIST
This button resets CIST general parameters to their default values.
NOTE:
IEEE 802.1w standard-based RSTP implementation runs on one STG (i.e. same as one spanning tree instance) only.
As a result, if „RSTP‟ is selected as the MSTP/RSTP mode, then only a single RSTP instance (default for STG 1) is
supported for all VLANs, including the Default VLAN 1.
If multiple spanning tree instances are required, then select „MSTP‟ mode, so that multiple VLANs are handled by
multiple spanning tree instances, as specified by IEEE 802.1s standard-based MSTP implementation.
Only IEEE 802.1s MSTP supports rapid convergence using IEEE 802.1w RSTP.
PVST+ does not support rapid convergence in current versions.
NOTE:
The following configurations are unsupported:
1 PVST+ (default Spanning Tree setting) is NOT interoperable with Cisco Rapid PVST+.
2 MSTP/RSTP (with mode set to either „mstp‟ or „rstp‟) is NOT interoperable with Cisco Rapid PVST+.
The following configurations are supported:
1 PVST+ (default Spanning Tree setting) is interoperable with Cisco PVST+.
2 MSTP/RSTP (with mode set to „mstp‟) is interoperable with Cisco MST/RSTP.