Technical data

BLADE OS 5.1 Application Guide
BMD00136, November 2009 Chapter 5: Spanning Tree Group
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Figure 9 Two VLANs on one Spanning Tree Group
In Figure 10, VLAN 1 and VLAN 2 belong to different Spanning Tree Groups. The two instances of
Spanning Tree separate the topology without forming a loop. Both VLANs can forward packets
between the switches without losing connectivity.
Figure 10 Two VLANs, each on a different Spanning Tree Group
Switch 1
VLAN 1, STG 1
Switch 2
VLAN 2, STG 1
X
VLAN 2 traffic blocked by STG 1
Switch 1
VLAN 1, STG 1
Switch 2
VLAN 2, STG 2
VLAN 1 passes traffic on STG 1
VLAN 2 passes traffic on STG 2