User guide

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Cisco WLAN Controller Web Interface User Guide
OL-7416-04
Chapter 4 Controller Menu Bar Selection
Controller Spanning Tree Configuration
Controller Spanning Tree Configuration
Use CONTROLLER > Spanning Tree to navigate to this page.
The Spanning Tree Protocol (STP) is a link management protocol. Cisco WLAN Solution implements
the IEEE 802.1D standard for media access control bridges.
Using the spanning tree algorithm provides redundancy while preventing undesirable loops in a network
that are created by multiple active paths between stations. STP allows only one active path at a time
between any two network devices (this prevents the loops) but establishes the redundant links as a
backup if the initial link should fail.
This page allows you to enable or disable the spanning tree algorithm, modify its characteristics and
view statistics as described in the following tables.
Ta b l e 4 - 11 S T P P a ra m e t e r s
Parameter Description
Spanning Tree
Algorithm
Specifies if this controller participates in the spanning tree protocol. May be
enabled or disabled by selecting the corresponding line on the pull-down entry
field. The factory default is disabled.
Priority The value of the writable portion of the Bridge ID, i.e., the first two octets of
the (8 octet long) Bridge ID. The other (last) 6 octets of the Bridge ID are given
by the value of Bridge MAC Address. The value may be specified as a number
between 0 and 65535. The factory default is 32768.
Maximum Age
(seconds)
The value that all bridges use for MaxAge when this bridge is acting as the
root. Note that 802.1D-1990 specifies that the range for this parameter is
related to the value of Stp Bridge Hello Time. The granularity of this timer is
specified by 802.1D-1990 to be 1 second. Valid values are 6 through 40
seconds. The factory default is 20.
Hello Time (seconds) The value that all bridges use for HelloTime when this bridge is acting as the
root. The granularity of this timer is specified by 802.1D-1990 to be 1 second.
Valid values are 1 through 10 seconds. The factory default is 2.
Forward Delay
(seconds)
The value that all bridges use for ForwardDelay when this bridge is acting as
the root. Note that 802.1D-1990 specifies that the range for this parameter is
related to the value of Stp Bridge Maximum Age. The granularity of this timer
is specified by 802.1D-1990 to be 1 second. An agent may return a badValue
error if a set is attempted to a value that is not a whole number of seconds. Valid
values are 4 through 30 seconds. The Factory default is 15.
Spanning Tree
Specification
An indication of what version of the Spanning Tree Protocol is being run. IEEE
802.1D implementations return 'IEEE 802.1D'. If future versions of the IEEE
Spanning Tree Protocol are released that are incompatible with the current
version a new value will be defined.