Callback URL verification

When saving webhook subscription details, the Switch VTN verifies that the supplied callback URL is active and belongs to the VEN that creates the subscription. If the callback URL is not verified successfully, you will not be able to save the subscription using that URL.

How it works

Before saving the subscription details, the Switch VTN sends a GET request to the provided callback URL that includes a challenge, a query string parameter named echo, with random generated string value.

When the VEN receives this request on the callback URL, it MUST respond with 200 OK response and include the query string parameter value in the body of the response. The Switch VTN will verify that the echo parameter value that was sent back is the same as the one that was initially sent.

In case when the validation fails, the Switch VTN will not save the subscription details.