Configuring Retransmission Interval and Retry Count

Finding Feature Information

Your software release may not support all of the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.

Prerequisites for Configuring the Access Point Retransmission Interval and Retry Count

  • You can configure the retransmission intervals and retry count both at a global and a specific access point level. A global configuration applies these configuration parameters to all the access points. Alternatively, when you configure the retransmission level and retry count at a specific access point level, the values are applied to that particular access point. The access point specific configuration has a higher precedence than the global configuration.

Information About Retransmission Interval and Retry Count

The switch and the access points exchange packets using the Control and Provisioning of Wireless Access Points (CAPWAP) reliable transport protocol. For each request, a response is defined. This response is used to acknowledge the receipt of the request message. Response messages are not explicitly acknowledged; therefore, if a response message is not received, the original request message is retransmitted after the retransmit interval. If the request is not acknowledged after a maximum number of retransmissions, the session is closed and the access points reassociate with another switch.

How to Configure Access Point Retransmission Interval and Retry Count

Configuring the Access Point Retransmission Interval and Retry Count (CLI)

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. ap capwap retransmit interval interval_time
  4. ap capwap retransmit count count_value
  5. end
  6. ap name Cisco_AP capwap retransmit interval interval_time
  7. ap name Cisco_AP capwap retransmit count count_value
  8. show ap capwap retransmit

DETAILED STEPS

  Command or Action Purpose
Step 1

enable

Example:

Switch# enable

Enters privileged EXEC mode.
Step 2

configure terminal

Example:

Switch# configure terminal

Enters global configuration mode.
Step 3

ap capwap retransmit interval interval_time

Example:

Switch(config)# ap capwap retransmit interval 2

Configures the control packet retransmit interval for all access points globally.

Note 

The range for the interval parameter is from 2 to 5.
Step 4

ap capwap retransmit count count_value

Example:

Switch(config)# ap capwap retransmit count 3

Configures the control packet retry count for all access points globally.

Note 

The range for the count is from 3 to 8.
Step 5

end

Example:

Switch(config)# end

Returns to privileged EXEC mode. Alternatively, you can also press Ctrl-Z to exit global configuration mode.

Step 6

ap name Cisco_AP capwap retransmit interval interval_time

Example:

Switch# ap name AP02 capwap retransmit
 interval 2

Configures the control packet retransmit interval for the individual access point that you specify.

Note 

The range for the interval is from 2 to 5.
Note 

You must be in privileged EXEC mode to use the ap name commands.

Step 7

ap name Cisco_AP capwap retransmit count count_value

Example:

Switch# ap name AP02 capwap retransmit
 count 3

Configures the control packet retry count for the individual access point that you specify.

Note 

The range for the retry count is from 3 to 8.
Step 8

show ap capwap retransmit

Example:

Switch# show ap capwap retransmit

Displays the CAPWAP retransmit details.

Configuring the Access Point Retransmission Interval and Retry Count (GUI)

Procedure

  • Global configuration applicable to all APs:

    1. Choose Configuration > Wireless > Access Points > Global AP Configuration.

      The Global Configuration page is displayed.

    2. In the AP Retransmit Config Parameters area, enter the values for the following parameters:

      • AP Retransmit Count—Number of times you want the access point to retransmit the request to the switch. The valid range is between 3 and 8.

      • AP Retransmit Interval—Duration between the retransmission of requests. The valid range is between 2 and 5.

    3. Click Apply.

    4. Click Save Configuration.

  • Configuration that is applicable to a specific AP:

    1. Choose Configuration > Wireless > Access Points > All APs.

      The All APs page is displayed with a list of access points.

    2. Click the access point name.

      The AP > Edit page is displayed.

    3. Click the Advanced tab.

    4. In the AP Retransmit Config Parameters area, enter the values for the following AP Retransmit Count and AP Retransmit Interval parameters:

      • AP Retransmit Count—Number of times you want the access point to retransmit the request to the switch. The valid range is between 3 and 8.

      • AP Retransmit Interval—Duration between the retransmission of requests. The valid range is between 2 and 5.

    5. Click Apply.

    6. Click Save Configuration.

Viewing CAPWAP Maximum Transmission Unit Information (CLI)

SUMMARY STEPS

  1. enable
  2. show ap name Cisco_AP config general

DETAILED STEPS

  Command or Action Purpose
Step 1

enable

Example:

Switch# enable

Enters privileged EXEC mode.
Step 2

show ap name Cisco_AP config general

Example:

Switch# show ap name Maria-1250 config general | include MTU

Displays the maximum transmission unit (MTU) for the CAPWAP path on the switch. The MTU specifies the maximum size of any packet (in bytes) in a transmission.

Viewing CAPWAP Maximum Transmission Unit Information (GUI)

Procedure

Step 1

Choose Configuration > Wireless > Access Points > All APs.

The All APs page is displayed.

Step 2

Click the AP name.

The AP > Edit page is displayed.

Step 3

Click the Advanced tab.

The CAPWAP MTU field shows the CAPWAP maximum retransmission unit information.

Configuration Examples for Configuring Access Point Retransmission Interval and Retry Count

Viewing the CAPWAP Retransmission Details: Example

Enter the following command:

Switch# show ap capwap retransmit
Global control packet retransmit interval : 3
Global control packet retransmit count : 5

AP Name                           Retransmit Interval             Retransmit Count                
--------------------------------- ------------------------------- --------------------------------
3602a                             5                               3

Viewing Maximum Transmission Unit Information: Example

This example shows how to view the maximum transmission unit (MTU) for the CAPWAP path on the switch. The MTU specifies the maximum size of any packet (in bytes) in a transmission: 

Switch# show ap name cisco-ap-name config general | include MTU
CAPWAP Path MTU.................................. 1500