HP 6400cl, Management Manual, Page: 172 / 664

Spanning-Tree Operation
Overview
configured with VLANs grouped into two instances, as follows:
VLANs Instance 1 Instance 2
10, 11, 12 Yes No
20, 21, 22 No Yes
The logical and physical topologies resulting from these VLAN/Instance
groupings result in blocking on different links for different VLANs:
Switch “C”
Instance 1
VLANs: 10, 11, 12
Switch “A”
Root for Instance 1
VLANs: 10, 11, 12
Switch “B”
Instance 1
VLANs: 10, 11, 12
Switch “C”
Instance 2
VLANs: 20, 21, 22
Switch “A”
Instance 2
VLANs: 20, 21, 22
Switch “B”
Root for Instance 2
VLANs: 20, 21, 22
Switch “C”
Switch “A”
Root for Instance 1
Switch “B”
Root for Instance 2
Path blocked for VLANs in instance 1.
Path blocked for VLANs in instance 2.
Region “A”: Logical Topology
Path blocked for VLANs in instance 1.
Path blocked for VLANs in instance 2.
Region “A”: Physical Topology
Figure 6-1. Example of a Multiple Spanning-Tree Application
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