Chapter
Advanced Configuration
2
24-Port 10/100 + 2-Port 10/100/1000 Gigabit Advanced Smart Switch with 2 Combo SFPs
Spanning Tree > MSTP Properties
When using STP or RSTP, it may be difficult to maintain
a stable path between all VLAN members. Frequent
changes in the tree structure can easily isolate some of
the group members. MSTP (which is based on RSTP for
fast convergence) is designed to support independent
spanning trees based on VLAN groups. Using multiple
spanning trees can provide multiple forwarding paths and
enable load balancing. One or more VLANs can be grouped
into a Multiple Spanning Tree Instance (MSTI). MSTP builds
a separate Multiple Spanning Tree (MST) for each instance
to maintain connectivity among each of the assigned
VLAN groups. MSTP then builds an Internal Spanning Tree
(IST) for the Region containing all commonly configured
MSTP bridges.
An MST Region consists of a group of interconnected
bridges that have the same MST Configuration
Identifiers (including the Region Name, Revision Level
and Configuration Digest). An MST Region may contain
multiple MSTP Instances. An Internal Spanning Tree (IST)
is used to connect all the MSTP switches within an MST
region. A common Spanning Tree (CST) interconnects all
adjacent MST Regions, and acts as a virtual bridge node
for communications with STP or RSTP nodes in the global
network.
MSTP connects all bridges and LAN segments with a
single Common and Internal Spanning Tree (CIST). The
CIST is formed as a result of the running spanning tree
algorithm between switches that support the STP, RSTP,
MSTP protocols.
Spanning Tree > MSTP Properties
MSTP Settings
Enable MSTP
Enables MSTP.
Region Name (Max. 2 chars.)
The name for this MSTI.
Revision Level (0-)
The revision for this MSTI.
(Default:
0
)
Bridge Setting
Max Age (-40 sec)
Specifies the device Maximum Age
Time. The Maximum Age Time indicates the amount of time
in seconds a bridge waits before sending configuration
messages. The default max age is
20 seconds
. The range
is 6 to 40 seconds.
Forward Delay (4-0 sec)
Specifies the device forward
delay time. The Forward Delay Time indicates the amount
of time in seconds a bridge remains in a listening and
learning state before forwarding packets. The default is
1 seconds
. The range is 4 to 30 seconds.
Max Hops (1-40)
Specifies the maximum number of hops
allowed in the MST region before a BPDU is discarded
(Range: 1-40; Default:
20
)
Click
Save Settings
to save the changes.
Spanning Tree > MSTP Port Settings
Spanning Tree > MSTP Port Settings
Port
Displays the port number.
Port Fast
Indicates if the port is the edge of the network.
Force Point-to-Point Link Mode
Displays the Point-to-
Point Link Status.
Migration Check
Displays the Migration Check Status.
Change Settings
Port
Indicates the port on which Multiple STP is enabled.
Port Fast
Indicates if the port has been designated as a
port fast port. If the port has been designated port fast,
the port immediately transitions to the forwarding state.