Configuring Data Encryption

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 Data Encryption

  • Cisco 1260, 3500, 3600, 801, 1140, 1310, and 1520 series access points support Datagram Transport Layer Security (DTLS) data encryption.

  • You can use the switch to enable or disable DTLS data encryption for a specific access point or for all access points.

  • Non-Russian customers who use the Cisco switch do not need a data DTLS license.

Restrictions for Configuring Data Encryption

  • Encryption limits throughput at both the switch and the access point, and maximum throughput is desired for most enterprise networks.

  • If your switch does not have a data DTLS license and if the access point associated with the switch has DTLS enabled, the data path will be unencrypted.

  • In images that do not have a DTLS license, the DTLS commands are not available.

Information About Data Encryption

The switch enables you to encrypt Control and Provisioning of Wireless Access Points (CAPWAP) control packets (and optionally, CAPWAP data packets) that are sent between the access point and the switch using DTLS. DTLS is a standards-track Internet Engineering Task Force (IETF) protocol based on TLS. CAPWAP control packets are management packets exchanged between a switch and an access point while CAPWAP data packets encapsulate forwarded wireless frames. CAPWAP control and data packets are sent over separate UDP ports: 5246 (control) and 5247 (data). If an access point does not support DTLS data encryption, DTLS is enabled only for the control plane, and a DTLS session for the data plane is not established.

How to Configure Data Encryption

Configuring Data Encryption (CLI)

SUMMARY STEPS

    1.    configure terminal

    2.    ap link-encryption

    3.    end

    4.    show ap link-encryption

    5.    show wireless dtls connections


DETAILED STEPS
     Command or ActionPurpose
    Step 1 configure terminal


    Example: 
    Switch# configure terminal
     

    Enters global configuration mode.

     
    Step 2ap link-encryption


    Example: 
    Switch(config)# ap link-encryption
     

    Enables data encryption for all access points or a specific access point by entering this command. The default value is disabled.

    Changing the data encryption mode requires the access points to rejoin the switch.

     
    Step 3end


    Example:
    Switch(config)# end
     

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

     
    Step 4show ap link-encryption


    Example:
    Switch# show ap link-encryption
     

    Displays the encryption state of all access points or a specific access point. This command also shows authentication errors, which track the number of integrity check failures and replay errors. Relay errors help in tracking the number of times the access point receives the same packet.

     
    Step 5show wireless dtls connections


    Example:
    Switch# show wireless dtls
 connections
     

    Displays a summary of all active DTLS connections.

    Note   

    If you experience any problems with DTLS data encryption, enter the debug dtls ap {all | event | trace} command to debug all DTLS messages, events, or traces.

     

    Configuring Data Encryption (GUI)

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

      The All APs page is displayed.

      Step 2   Click the name of the access point for which you want to enable data encryption.

      The AP > Edit page is displayed.

      Step 3   Click the Advanced tab.
      Step 4   Select or unselect the Data Encryption check box.
      Note   

      Changing the data encryption mode requires the access points to reassociate with the switch.

      Step 5   Click Apply.
      Step 6   Click Save Configuration.

      Configuration Examples for Configuring Data Encryption

      Displaying Data Encryption States for all Access Points: Examples

      This example shows how to display the encryption state of all access points or a specific access point. This command also shows authentication errors, which track the number of integrity check failures and replay errors. Relay errors help in tracking the number of times the access point receives the same packet:

      Switch# show ap link-encryption
                    Encryption  Dnstream  Upstream    Last
AP Name                  State     Count     Count  Update
------------------  ----------  --------  --------  ------
3602a                  Enabled         0         0   Never

      This example shows how to display a summary of all active DTLS connections:

      Switch# show wireless dtls connections
AP Name         Local Port   Peer IP       Peer Port  Ciphersuite
--------------- ------------ ------------- ---------- --------------------
3602a           Capwap_Ctrl  10.10.21.213  46075      TLS_RSA_WITH_AES_128_CBC_SHA
3602a           Capwap_Data  10.10.21.213  46075      TLS_RSA_WITH_AES_128_CBC_SHA