Configuring the Retransmission Interval and Retry Count
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Configuring the Retransmission Interval and Retry CountConfiguring the Retransmission Interval and Retry Count
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Configuring the Retransmission Interval and Retry Count

Finding Feature Information

Your software release may not support all 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 Counts (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 ActionPurpose
    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 4ap 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 5end


    Example:
    Switch(config)# end
     

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

     
    Step 6ap 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.

     
    Step 7ap 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 8show ap capwap retransmit


    Example:
    Switch# show ap capwap retransmit
     

    Displays the CAPWAP retransmit details.

     

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

      Step 1   Configure the switch to set the retransmission interval and retry count globally using the switch GUI as follows:
      1. Choose Monitor > AP Summary > Global AP Configuration

        The Global Configuration page appears.

      2. Choose one of the following options under the AP Transmit Config Parameters area:
        • AP Retransmit Count—Enter the number of times you want the access point to retransmit the request to the switch. The range is from 3 to 8.
        • AP Retransmit Interval—Enter the time duration between the retransmission of requests. The range is from 2 to 5.
      Step 2   Configure the switch to set the retransmission interval and retry count for a specific access point as follows:
      1. Choose Configuration > Wireless > AP Summary.

        The All APs page appears with a list of access points.

      2. Click the access point for which you want to configure retransmit interval and retry count parameters.

        The AP > Edit page appears.

      3. Click Advanced.
      4. In the AP Retransmit Config Parameters area, select the check box that corresponds to the AP Retransmit Count field.

        The AP Retransmit Count field is enabled.

      5. In the AP Retransmit Count field, enter the number of times that you want the access point to retransmit the request to the switch.
        Note   

        The range is from 2 to 5.

      6. In the AP Retransmit Config Parameters area, select the check box that corresponds to the AP Retransmit Interval field.

        The AP Retransmit Interval field is enabled.

      7. In the AP Retransmit Interval field, enter the time duration between the retransmission of requests.
        Note   

        The range is from 3 to 8.

      8. Click Apply.

      Monitoring CAPWAP Maximum Transmission Unit Information (CLI)


      Note

      The procedure to perform this task using the switch GUI is not currently available.

      SUMMARY STEPS

        1.    enable

        2.    show ap name Cisco_AP config general


      DETAILED STEPS
         Command or ActionPurpose
        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.

         

        Debugging CAPWAP


        Note

        The procedure to perform this task using the switch GUI is not currently available.

        SUMMARY STEPS

          1.    enable

          2.    debug capwap {ap all | cert-management | critical | detail | dtls-keepalive | error | events | ha [detail | dump | event | hex-dump | information | packet | payload | state} [switch switch_number]


        DETAILED STEPS
           Command or ActionPurpose
          Step 1 enable


          Example: 
          Switch# enable
           

          Enters privileged EXEC mode.

           
          Step 2debug capwap {ap all | cert-management | critical | detail | dtls-keepalive | error | events | ha [detail | dump | event | hex-dump | information | packet | payload | state} [switch switch_number]


          Example:
           Switch# debug capwap ap all
           

          Enables debugging of CAPWAP data.

          You can use any one of the following keywords with the command to enable debugging of various CAPWAP parameters:

          • all—Enables debugging all CAPWAP data.
          • cert-management—Enables debugging of CAPWAP certificate management.
          • critical—Enables debugging of critical CAPWAP data.
          • details—Enables debugging of CAPWAP details.
          • dtls-keepalive—Enables debugging of dtls keepalive packets.
          • error—Enables debugging of CAPWAP errors.
          • events—Enables debugging of CAPWAP events.
          • ha—Enables debugging of high availability in CAPWAP.
          • hexdump—Enables debugging of a CAPWAP hexadecimal dump.
          • information—Enables debugging of CAPWAP information.
          • packets—Enables debugging of CAPWAP packets.
          • payload—Enables debugging of a CAPWAP payload.
          • state—Enables debugging of CAPWAP states.
           

          Configuration Examples for Configuring Access Point Retransmission Interval and Retry Count

          Displaying the CAPWAP Retransmission Details: Example

          This example shows how to display the CAPWAP retransmit details:

          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

          Displaying Maximum Transmission Unit Information: Example

          This example shows how to display 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 Maria-1250 config general | include MTU
CAPWAP Path MTU.................................. 1500