Spanning Tree Algorithm
10-16
10
Configuring Multiple Spanning Trees
MSTP generates a unique spanning tree for each instance. This provides multiple
pathways across the network, thereby balancing the traffic load, preventing
wide-scale disruption when a bridge node in a single instance fails, and allowing for
faster convergence of a new topology for the failed instance.
By default all VLANs are assigned to the Internal Spanning Tree (MST Instance 0)
that connects all bridges and LANs within the MST region. This switch supports up
to 33 instances. You should try to group VLANs which cover the same general area
of your network. However, remember that you must configure all bridges within the
same MSTI Region (page 10-8) with the same set of instances, and the same
instance (on each bridge) with the same set of VLANs. Also, note that RSTP treats
each MSTI region as a single node, connecting all regions to the Common Spanning
Tree.
To use multiple spanning trees:
1. Set the spanning tree type to MSTP (STA Configuration, page 10-6).
2. Enter the spanning tree priority for the selected MST instance (MSTP VLAN
Configuration).
3. Add the VLANs that will share this MSTI (MSTP VLAN Configuration).
Note:
All VLANs are automatically added to the IST (Instance 0).
To ensure that the MSTI maintains connectivity across the network, you must
configure a related set of bridges with the same MSTI settings.
Command Attributes
•
MST Instance
– Instance identifier of this spanning tree. (Default: 0)
•
Priority
– The priority of a spanning tree instance. (Range: 0-61440 in steps of
4096; Options: 0, 4096, 8192, 12288, 16384, 20480, 24576, 28672, 32768, 36864,
40960, 45056, 49152, 53248, 57344, 61440; Default: 32768)
•
VLANs in MST Instance
– VLANs assigned this instance.
•
MST ID
– Instance identifier to configure. (Range: 0-4094; Default: 0)
•
VLAN
ID
– VLAN to assign to this selected MST instance. (Range: 1-4093)
The other global attributes are described under “Displaying Global Settings,” page 10-3. The
attributes displayed by the CLI for individual interfaces are described under “Displaying Interface
Settings,” page 10-10
Summary of Contents for 8926EM
Page 6: ...ii ...
Page 34: ...Getting Started ...
Page 44: ...Introduction 1 10 1 ...
Page 62: ...Initial Configuration 2 18 2 ...
Page 64: ...Switch Management ...
Page 76: ...Configuring the Switch 3 12 3 ...
Page 118: ...Basic Management Tasks 4 42 4 ...
Page 164: ...User Authentication 6 28 6 ...
Page 176: ...Access Control Lists 7 12 7 ...
Page 284: ...Quality of Service 14 8 14 ...
Page 294: ...Multicast Filtering 15 10 15 ...
Page 300: ...Domain Name Service 16 6 16 ...
Page 310: ...Dynamic Host Configuration Protocol 17 10 17 ...
Page 320: ...Configuring Router Redundancy 18 10 18 ...
Page 344: ...IP Routing 19 24 19 ...
Page 356: ...Unicast Routing 20 12 20 Web Click Routing Protocol RIP Statistics Figure 20 5 RIP Statistics ...
Page 386: ...Unicast Routing 20 42 20 ...
Page 388: ...Command Line Interface ...
Page 400: ...Overview of the Command Line Interface 21 12 21 ...
Page 466: ...SNMP Commands 24 16 24 ...
Page 520: ...Access Control List Commands 26 18 26 ...
Page 546: ...Rate Limit Commands 30 2 30 ...
Page 612: ...VLAN Commands 34 24 34 ...
Page 626: ...Class of Service Commands 35 14 35 ...
Page 670: ...DHCP Commands 39 16 39 ...
Page 716: ...IP Interface Commands 41 36 41 ...
Page 768: ...IP Routing Commands 42 52 42 ...
Page 770: ...Appendices ...
Page 791: ......