Cisco Cisco 2106 Wireless LAN Controller
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Release Notes for Cisco Wireless LAN Controllers and Lightweight Access Points for Release 5.2.178.0
OL-31336-01
Important Notes for Controllers and Non-Mesh Access Points
Configuration File Stored in XML
In controller software release 4.2.61.0 and later, the controller’s bootup configuration file is stored in an
Extensible Markup Language (XML) format rather than in binary format. When you upgrade a controller
to 4.2.61.0 or a later software release, the binary configuration file is migrated and converted to XML.
Extensible Markup Language (XML) format rather than in binary format. When you upgrade a controller
to 4.2.61.0 or a later software release, the binary configuration file is migrated and converted to XML.
Note
You cannot download a binary configuration file onto a controller running software release 5.2.178.0.
Also, do not attempt to make changes to the configuration file. If you do so and then download the file
to a controller, the controller displays a cyclic redundancy checksum (CRC) error while it is rebooting
and returns the configuration parameters to their default values.
Also, do not attempt to make changes to the configuration file. If you do so and then download the file
to a controller, the controller displays a cyclic redundancy checksum (CRC) error while it is rebooting
and returns the configuration parameters to their default values.
Note
You cannot modify the configuration files for 2000, 4000, and 4100 series controllers. The ability to
modify configuration files is available in controller software release 5.2 or later, and these controllers
support only earlier software releases (up to the 4.2 release for 2000 series controllers and up to the 3.2
release for 4000 and 4100 series controllers).
modify configuration files is available in controller software release 5.2 or later, and these controllers
support only earlier software releases (up to the 4.2 release for 2000 series controllers and up to the 3.2
release for 4000 and 4100 series controllers).
LWAPP Mode Changes
When you upgrade to controller software release 5.0.148.0 or later, the LWAPP mode changes to Layer
3 if it was previously configured for Layer 2.
3 if it was previously configured for Layer 2.
If you downgrade from controller software release 5.2.178.0, 5.2.157.0, 5.1.151.0, or 5.0.148.0 to
4.2.61.0 or an earlier release, the LWAPP mode changes from Layer 3 to Layer 2. Access points might
not join the controller, and you must manually reset the controller to Layer 3 to resolve this issue.
4.2.61.0 or an earlier release, the LWAPP mode changes from Layer 3 to Layer 2. Access points might
not join the controller, and you must manually reset the controller to Layer 3 to resolve this issue.
Access Points Send Multicast and Management Frames at Highest Basic Rate
Access points running recent Cisco IOS versions transmit multicast and management frames at the
highest configured basic rate, which could cause reliability problems. Access points running LWAPP or
autonomous IOS should transmit multicast and management frames at the lowest configured basic rate.
Such behavior is necessary to provide good coverage at the cell’s edge, especially for unacknowledged
multicast transmissions where multicast wireless transmissions may fail to be received.
highest configured basic rate, which could cause reliability problems. Access points running LWAPP or
autonomous IOS should transmit multicast and management frames at the lowest configured basic rate.
Such behavior is necessary to provide good coverage at the cell’s edge, especially for unacknowledged
multicast transmissions where multicast wireless transmissions may fail to be received.
Because multicast frames are not retransmitted at the MAC layer, clients at the edge of the cell may fail
to receive them successfully. If reliable reception is a goal, then multicast frames should be transmitted
at a low data rate. If support for high data rate multicast frames is required, then it may be useful to shrink
the cell size and disable all lower data rates.
to receive them successfully. If reliable reception is a goal, then multicast frames should be transmitted
at a low data rate. If support for high data rate multicast frames is required, then it may be useful to shrink
the cell size and disable all lower data rates.
Depending on your specific requirements, you can take the following action:
•
If you need to transmit multicast data with the greatest reliability and if there is no need for great
multicast bandwidth, then configure a single basic rate, one that is low enough to reach the edges of
the wireless cells.
multicast bandwidth, then configure a single basic rate, one that is low enough to reach the edges of
the wireless cells.
•
If you need to transmit multicast data at a certain data rate in order to achieve a certain throughput,
then configure that rate as the highest basic rate. You can also set a lower basic rate for coverage of
non-multicast clients.
then configure that rate as the highest basic rate. You can also set a lower basic rate for coverage of
non-multicast clients.