Lucent Technologies P550 - Manual (Page 229)

Using VLANs, Spanning Tree, and Hunt Groups (Layer 2 and Layer 3)
Cajun P550/P220 Switch Operation Guide 12-7
Spanning Tree Bridge Options
The three spanning tree options are:
❒ If you use the default 802.1D spanning tree option, the entire switch is a bridge, for
which spanning tree parameters can be set. Every port, regardless of VLAN
membership, is part of the same spanning tree. The implication is that after
resolving the spanning tree topology, only one trunk will be active, and all others
will be blocked.
❒ If you use the Spanning Tree per VLAN option, each VLAN runs a separate
spanning tree with its own BPDUs. This allows different ports to blocked or
unblocked on different VLANs.
❒ If you use the dual layer spanning tree option, within a set of interconnected Cajun
switches, you can set up a separate spanning tree for each VLAN. The switch then
runs a second level of spanning tree to control routes between switches in the
Cajun Network. This creates smaller spanning tree domains and provides quicker
convergence upon reconfiguration.
Managing Spanning Trees
To manage spanning trees:
1. In the Switching Parameters section of the Web Agent window, click Spanning
Tree. The Spanning Tree Information dialog box opens.
2. From the Configuration pull-down menu, select the type of spanning tree you
want to implement.
3. Use Table 12-3 to select your Spanning Tree options: