Alcatel OmniSwitch 6800 Series Network Configuration Manual page 101

Configuring Spanning Tree Parameters
The hello time propagated in a root bridge Configuration BPDU is the value used by all other bridges in
the tree for their own hello time. Therefore, if this value is changed for the root bridge (VLAN), all other
VLANs associated with the same STP instance will adopt this value as well.
If the switch is running in the 1x1 Spanning Tree mode, then a hello time value is defined for each VLAN.
When a VLAN is created, STP is enabled and the hello time defaults to 2 seconds. If the switch is running
in the flat Spanning Tree mode, then a hello time value is defined for instance 0. Lowering the hello time
interval improves the robustness of the Spanning Tree topology. However, increasing the hello time inter-
val reduces Spanning Tree overhead.
To change the VLAN bridge hello time, enter bridge followed by an existing VLAN ID (or 0 if using the
flat STP instance) then hello time followed by a numerical value between 1 and 10 to specify the number
of seconds. For example, the following commands change the hello time value for VLAN 455 to 5
seconds and the hello time value for the flat STP instance to 8:
-> bridge 455 hello time 5
-> bridge 0 hello time 8
To view the VLAN bridge hello time value, use the
this command, see the OmniSwitch CLI Reference Guide.
OmniSwitch 6800 Series Network Configuration Guide
Configuring STP VLAN Parameters
show spantree command. For more information about
November 2004 page 5-13