Configuring Spanning Tree
Defining Spanning Tree
Cisco Small Business SFE/SGE Managed Switches Administration Guide
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BPDU Handling — Determines how BPDU packets are managed when STP is
disabled on the port or device. BPDUs are used to transmit spanning tree
information. The possible field values are:
-
Filtering
— Filters BPDU packets when spanning tree is disabled on an
interface.
-
Flooding
— Floods BPDU packets when spanning tree is disabled on an
interface. This is the default value.
•
Path Cost Default Values — Specifies the method used to assign default path
costs to STP ports. The possible field values are:
-
Short
— Specifies 1 through 65,535 range for port path costs.
-
Long
— Specifies 1 through 200,000,000 range for port path costs.The
default path costs assigned to an interface varies according to the
selected method. This is the default value.
The Bridge Settings area contains the following fields:
•
Priority — Specifies the bridge priority value. When switches or bridges are
running STP, each is assigned a priority. After exchanging BPDUs, the device
with the lowest priority value becomes the Root Bridge. The default value is
32768. The bridge priority value is provided in increments of 4096. For
example, 4096, 8192, 12288, etc. The range is 0 to 61440.
•
Hello Time — Specifies the device Hello Time. The Hello Time indicates the
amount of time in seconds a root bridge waits between configuration
messages. The default is 2 seconds. The range is 1 to 10 seconds.
•
Max Age — Specifies the device Maximum Age Time. The Maximum Age Time
indicates the amount of time in seconds that the device can wait without
receiving a configuration message, before attempting to redefine its own
configuration. The default max age is 20 seconds. The range is 6 to 40
seconds.
•
Forward Delay — Specifies the device forward delay time. The Forward Delay
Time indicates the amount of time in seconds a bridge remains in a learning
state before forwarding packets. The default is 15 seconds. The range is 4 to
30 seconds.
The Designated Root area contains the following fields:
•
Bridge ID — Identifies the Bridge Priority and MAC address.
•
Root Bridge ID— Identifies the Root Bridge priority and MAC address.