Brocade Network OS Administrator’s Guide v4.1.1 - Manual (Page 420)

Shutting down STP, RSTP, MSTP, PVST+, or R-PVST+ globally
To shut down STP, RSTP, MSTP, PVST+, or R-PVST+ globally, perform the following steps from
privileged EXEC mode.
1. Enter the configure terminal command to change to global configuration mode.
switch# configure terminal
2. Enter the shutdown command to globally shutdown STP, RSTP, MSTP, PVST+, or R-PVST+. The
shutdown command below works in all modes.
switch(config-mstp)# shutdown
Specifying bridge parameters
There are a variety of options for configuring the behavior of the STP bridging function, as shown in
the following subsections.
Specifying the bridge priority
In PVST+ or R-PVST+ mode, use the bridge-priority command to specify the priority of the switch.
After you decide on the root switch, set the appropriate values to designate the switch as the root
switch. If a switch has a bridge priority that is lower than that of all the other switches, the other
switches automatically select the switch as the root switch.
The root switch should be centrally located and not in a "disruptive" location. Backbone switches
typically serve as the root switch because they often do not connect to end stations. All other decisions
in the network, such as which port to block and which port to put in forwarding mode, are made from
the perspective of the root switch.
Bridge Protocol Data Units (BPDUs) carry the information exchanged between switches. When all
the switches in the network are powered up, they start the process of selecting the root switch. Each
switch transmits a BPDU to directly connected switches on a per-VLAN basis. Each switch compares
the received BPDU to the BPDU that the switch sent. In the root switch selection process, if switch 1
advertises a root ID that is a lower number than the root ID that switch 2 advertises, switch 2 stops the
advertisement of its root ID, and accepts the root ID of switch 1. The switch with the lowest bridge
priority becomes the root switch.
Additionally, you may specify the bridge priority for a specific VLAN. If the VLAN parameter is not
provided, the priority value is applied globally for all per-VLAN instances. However, for the VLANs that
have been configured explicitly, the per-VLAN configuration takes precedence over the global
configuration.
NOTE
On the Brocade VDX 8770, the VLAN value can be 1 through 4086. VLAN IDs 4087 through 4094 are
internally reserved VLAN IDs. On all other Brocade VDX switches, the VLAN value can be 1
through 3962, as 3963 through 4094 are reserved.
To specify the bridge priority, perform the following steps from privileged EXEC mode.
1. Enter the configure terminal command to change to global configuration mode.
switch# configure terminal
2. Enter the protocol command to enable PVST+ or R-PVST+.
switch(config)# protocol spanning-tree pvst
Shutting down STP, RSTP, MSTP, PVST+, or R-PVST+ globally
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