dot11 extension aironet

dot11 extension aironet 

There are several additional attributes provided with AE. Can be disabled sometimes for legacy clients to connect. 

Use the dot11 extension aironet configuration interface command to enable or disable Cisco Aironet extensions to the IEEE 802.11b standard. Use the no form of this command to disable the Cisco Aironet extensions.

[no] dot11 extension aironet

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Note You cannot disable Cisco Aironet extensions on bridges.

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Syntax Description

This command has no arguments or keywords.

Defaults

Cisco Aironet extensions are enabled by default.

Command Modes

Configuration interface

Command History

Release	Modification
12.2(4)JA	This command was introduced.

Usage Guidelines

The Cisco Aironet extensions help clients choose the best access point. You must enable these extensions to use advanced features such as Cisco MIC and key hashing. Disable these extensions for non-Cisco clients that misinterpret the extensions.

Examples

This example shows how to enable Cisco Aironet extensions for the radio interface:

AP(config-if)# dot11 extension aironet

This example shows how to disable Cisco Aironet extensions for the radio interface:

AP(config-if)# no dot11 extension aironet

What are the features supported by the Aironet Extension option?

A. The Aironet extension is a proprietary feature implemented by Cisco. Aironet extensions contains information elements that support these features.

• Load Balancing: The access point uses Aironet extensions to direct client devices to an access point that provides the best connection to the network based on factors such as the number of users, bit error rates, load and signal strength.
  Load balancing is proprietary between devices that understand the Aironet extensions. Load balancing is implemented by extensions in AP beacons and/or probe-responses, which provide information on these:
  
  • Base-station signal strength
    
  • Base station loading (% transmitter busy)
    
  • Number of hops to the backbone
    
  • Number of client associations
    
  The client evaluates these and associates to the "best" one. Non-Cisco clients do not understand these extensions.
  
• MIC: Cisco Proprietary Message Integrity Check (MIC) — MIC is an additional WEP security feature that prevents attacks on encrypted packets called bit-flip attacks. The MIC is implemented on both the access point and all associated client devices.
  
• Cisco Proprietary Temporal Key Integrity Protocol (CKIP), also known as WEP key hashing, is an additional WEP security feature that defends against an attack on WEP, in which the intruder uses an unencrypted segment called the initialization vector (IV) in encrypted packets to calculate the WEP key.
  
• In addition to these, Aironet extensions carry more information that include these:
  
  • Load that the AP currently handles
    
  • Number of hops from the Wired network
    
  • Device type, which helps identify the product under the Cisco system for management
    
  • Device name
    
  • Number of associated clients
    
  • Radio type, a feature used to determine certain characteristics about the radio, such as datarate, radio type (1310, 1200, 352 or 342), security type (WEP/802.1x), etc.
    

Devices that are CCX compatible also can take advantage of some of the Aironet Extension features. Here is a list of the features available with the different versions of Cisco Compatible Extensions:
Cisco Compatible Extensions - Versions and Features