Basic Clear ANC Endpoint Policy Notification Example

This sample registers and outputs messages received for Cisco Adaptive Network Control (ANC) clear endpoint policy notifications via DXL and Cisco pxGrid.

Prerequisites

• The samples configuration step has been completed (see Samples Configuration).
• The DXL fabric to which the client will connect has been bridged to Cisco pxGrid.
• The Python client has been authorized to receive DXL Cisco pxGrid Notifications (see Authorize Client to Use Cisco pxGrid via DXL).
• ANC Clear Endpoint Policy notifications from pxGrid have been enabled (see Enable Cisco pxGrid Notifications for DXL).

Running

To run this sample execute the sample/basic/basic_anc_clear_endpoint_policy_notification_example.py script as follows:

python sample/basic/basic_anc_clear_endpoint_policy_notification_example.py

After the example starts up, the initial output should appear similar to the following:

Waiting for clear policy events...

To generate a clear endpoint policy by IP address notification, run through the steps in the Basic Clear ANC Endpoint Policy by IP Address Example in a separate terminal command window. Assuming that a policy is successfully cleared, the following message should appear in the output of the notification example:

{
    "ipAddress": "192.168.1.1"
}

To generate a clear endpoint policy by MAC address notification, run through the steps in the Basic Clear ANC Endpoint Policy by MAC Address Example in a separate terminal command window. Assuming that a policy is successfully cleared, the following message should appear in the output of the notification example:

{
    "macAddress": "00:11:22:33:44:55"
}

Note that if the clear endpoint policy calls encounter any errors -- for example, due to no policy already having been applied -- no corresponding event notification will be generated.

Details

The majority of the sample code is shown below:

# Create the client
with DxlClient(config) as dxl_client:

    # Connect to the fabric
    dxl_client.connect()

    logger.info("Connected to DXL fabric.")

    # Create client wrapper
    client = CiscoPxGridClient(dxl_client)

    class MyAncClearEndpointPolicyCallback(AncClearEndpointPolicyCallback):
        def on_clear_endpoint_policy(self, clear_dict):
            print("on_clear_endpoint_policy\n" +
                  MessageUtils.dict_to_json(clear_dict, pretty_print=True))

    # Attach callback for 'clear policy' events
    client.anc.add_clear_endpoint_policy_callback(
        MyAncClearEndpointPolicyCallback())

    # Wait forever
    print("Waiting for clear policy events...")
    while True:
        time.sleep(60)

Once a connection is established to the DXL fabric, a dxlciscopxgridclient.client.CiscoPxGridClient instance is created which will be used to communicate with Cisco pxGrid.

Next, the dxlciscopxgridclient.client.AncClientCategory.add_clear_endpoint_policy_callback() method is invoked to register a callback for clear policy event notifications.

When a clear endpoint policy event occurs, the on_clear_endpoint_policy method in the MyAncClearEndpointPolicyCallback class is invoked. The clear_dict parameter passed into the callback, a dictionary (dict) which contains the content of the event notification, is displayed.