Consolidated Platform Configuration Guide, Cisco IOS XE 3.3SE (Catalyst 3850 Switches)
Configuring Retransmission Interval and Retry Count
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Configuring Retransmission Interval and Retry Count

Finding Feature Information

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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)

    • 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)


        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