Configuring Stp Bridge Parameters - Alcatel-Lucent OmniSwitch AOS Release 7 Manual

Configuring STP Bridge Parameters

priority of 16384, then spantree msti 2 priority 16384 is the command captured to reflect this in the snap-
shot file. In addition, explicit commands are captured for both flat and per-VLAN mode configurations.
Configuring STP Bridge Parameters
The Spanning Tree software is active on all switches by default and uses default bridge and port
parameter values to calculate a loop free topology. It is only necessary to configure these parameter values
if it is necessary to change how the topology is calculated and maintained.
Note the following when configuring Spanning Tree bridge parameters:
•
When a switch is running in the per-VLAN Spanning Tree mode, each VLAN is in essence a virtual
bridge with its own Spanning Tree instance and configurable bridge parameters.
•
When the switch is running in the flat mode and STP (802.1D) or RSTP (802.1w) is the active
protocol, bridge parameter values are only configured for the flat mode instance.
•
If MSTP (802.1s) is the active protocol, then the priority value is configurable for each Multiple
Spanning Tree Instance (MSTI). All other parameters, however, are still only configured for the flat
mode instance and are applied across all MSTIs.
•
Bridge parameter values for a VLAN instance are not active unless Spanning Tree is enabled on the
VLAN and at least one active port is assigned to the VLAN. Use the
command to enable or disable a VLAN Spanning Tree instance.
•
If Spanning Tree is disabled on a VLAN, active ports associated with that VLAN are excluded from
Spanning Tree calculations and remain in a forwarding state.
•
Note that when a switch is running in the flat mode, disabling Spanning Tree on VLAN 1 disables the
instance for all VLANs and all active ports are then excluded from any Spanning Tree calculations and
remain in a forwarding state.
The following is a summary of Spanning Tree bridge configuration commands. For more information
about these commands, see the OmniSwitch CLI Reference Guide.
Commands
spantree protocol
spantree priority
spantree hello-time
spantree max-age
spantree forward-delay
spantree bpdu-switching
page 5-26
Used for ...
Configuring the protocol for the flat mode CIST instance or a per-
VLAN mode VLAN instance.
Configuring the priority value for the flat mode CIST instance, a
Multiple Spanning Tree Instance (MSTI), or a per-VLAN mode
VLAN instance.
Configuring the hello time value for the flat mode CIST instance or
a per-VLAN mode VLAN instance.
Configuring the maximum age time value for the flat mode CIST
instance or a per-VLAN mode VLAN instance.
Configuring the forward delay time value for the flat mode CIST
instance or a per-VLAN mode VLAN instance.
Configuring the BPDU switching status for a VLAN.
OmniSwitch AOS Release 7 Network Configuration Guide
Configuring Spanning Tree Parameters
spantree vlan admin-state
March 2011