Network Interface Configuration
Configure radio interfaces through the IOS CLI

Now that all the setting have been covered in the IOS GUI, the student can now focus on learning the IOS CLI specifics of the AP. The first task in configuring the radio interface using the IOS CLI is to configure a SSID with open authentication. The commands are shown in Figure . The other authentication methods will be covered in the security Module. Next, delete the default SSID . A default 1200 AP configuration is shown in Figure . Keep in mind that the shutdown command can be used to disable a radio interface.

Use the station-role configuration interface command to set the role of the radio interface. Use the no form of the command to reset the parameter to the default value .

[no] station-role {repeater | root [fallback {shutdown | repeater]}}

Beyond the radio role, basic SSID, and open authentication, the radio power, speed, and channel can be modified for optimal performance or distance.

Use the power client maximum configuration interface command to configure the maximum power level clients should use for IEEE 802.11 radio transmissions to the access point. The power setting is transmitted to the client device during association with the access point. Use the no form of the command to not specify a power level . The example below shows how to specify a 20-mW power level for client devices associated to the access point radio:

AP(config-if)#power client 20

Use the power local configuration interface command to configure the access point radio power level. Use the no form of the command to reset the parameter to defaults . For a list of maximum power levels allowed in each regulatory domain for the 2.4-GHz and 5 GHz radio, see Figure . The example below shows how to specify a 20-mW transmit power level for one of the the access point radios.

AP(config-if)#power local 20

Use the speed configuration interface command to configure the data rates supported by the access point radios . An individual data rate can be set only to a basic or a non-basic setting, not both. The first example shows how to set the radio data rates for best throughput. The second example shows how to set the radio data rates support a low-speed client device while still supporting higher-speed client devices.

AP(config-if)#speed throughput
AP(config-if)#speedbasic-1.0 2.0 5.5 11.0

Use the channel configuration interface command to set the radio channel frequency. Use the no form of this command to reset the channel frequency to defaults . The syntax is as follows:

[no] channel {number | frequency | least-congested}

Figure shows the available frequencies (in MHz) for the 2.4-GHz radio and the 5-GHz radio.

By default, the access point uses Cisco Aironet 802.11 extensions to detect the capabilities of Cisco Aironet client devices and to support features that require specific interaction between the access point and associated client devices. Aironet extensions must be enabled to support the features such as load balancing, limiting power on the client, repeater mode, world mode, and advanced security mechanisms.

Clients who roam from one access point to another are supported with pre-standard services for seamless hand-off defined under IEEE 802.11f Inter-Access Point Protocol (IAPP). With this feature, when a client roams from a first access point to a second one, the second access point sends a message to the first to update its association table, establishing a learning path to the client for the switch. This feature provides backward compatibility with the Cisco Aironet Data Delivery Protocol for inter-access point hand-off as implemented on the Cisco Aironet 340, 350, and 1200 Series.

Disabling Aironet extensions disables the features listed above, but it sometimes improves the ability of non-Cisco client devices to associate to the access point. Aironet extensions are enabled by default. Beginning in privileged EXEC mode, follow these steps to disable Aironet extensions.

AP(config)#interface dot11radio { 0 | 1 }
AP(config-if)#no dot11 extension aironet

When the access point receives data packets that are not 802.3 packets, the access point must format the packets to 802.3 using an encapsulation transformation method. To configure this through the CLI, follow the steps below to set the encapsulation transformation method to RFC1042 (snap) or 802.1h (dot1h, the default setting).

AP(config)#interface dot11radio {0 | 1}
AP(config-if)#payload-encapsulation snap | dot1h

Figure displays many of the settings which can be configured on the radio interface.


Lab Activity

Lab Exercise: Configure Radio Interface through the IOS CLI

In this lab, the student will enter basic channel and data rate information for the AP radio.

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