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Cisco IOS Software Configuration Guide for Cisco Aironet Access Points
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Chapter19 Configuring Repeater and Standby Access Points and Wo rkgroup Bridge Mode
Understanding Workgroup Bridge Mode
You can also configure the periodicity of scans. When the connection conditions deteriorate, the
workgroup bridge scans for a better access point to connect to. If the scan does not allow the workgroup
bridge to find a better connection point, use the mobile station period number-of-seconds command to
determine the interval to the next scanning cycle.
Configuring a Workgroup Bridge for Limited Channel Scanning
In mobile environments such as railroads, a workgroup bridge instead of scanning all the channels will
be restricted to scan only a set of limited channels in order to reduce the hand-off delay when the
workgroup bridge roams from one access point to another. By limiting the number of channels the
workgroup bridge scans to only those required, the mobile workgroup bridge achieves and maintains a
continuous wireless LAN connection with fast and smooth roaming.

Configuring the Limited Channel Set

This limited channel set is configured using the mobile station scan <set of channels> CLI command
to invoke scanning to all or specified channels. There is no limitation on the maximum number of
channels that can be configured. The maximum number of channels that can be configured is restricted
only by the number of channels a radio can support. When executed, the workgroup bridge only scans
this limited channel set. This limited channel feature also affects the known channel list that the
workgroup bridge receives from the access point to which it is currently associated. Channels are added
to the known channel list only if they are also a part of the limited channel set.
The following example shows how the command is used. In the example, channels 1, 6, and 11 are
specified to scan:
ap#
ap#confure terminal
Enter configuration commands, one per line. End with CNTL/Z.
ap(config)#int d0
ap(config-if)#ssid limited_scan
ap(config-if)#station-role workgroup-bridge
ap(config-if)#mobile station
ap(config-if)#mobile station scan 1 6 11
ap(config-if)#end
ap#
Use the no mobile station scan command to restore scanning to all the channels.

Ignoring the CCX Neighbor List

In addition, the workgroup bridge updates its known channel list using CCX reports such as the AP
Adjacent report or Enhanced Neighbor List report. However, when a workgroup bridge is configured for
limited channel scanning, it does not need to process the CCX reports to update its known channel list.
Use the mobile station ignore neighbor-list command to disable processing of CCX neighbor list
reports. This command is effective only if the workgroup bridge is configured for limited scanning
channel scanning. The following example shows how this command is used
ap#
ap#confure terminal
Enter configuration commands, one per line. End with CNTL/Z.
ap(config)#int d0
ap(config-if)#mobile station ignore neighbor-list
ap(config-if)#end