Parameter name	Value	Required?	Description
url	A valid URL, such as http://server_name or http://server_name:1234	No. However, if the url or resourcename parameters are not specified, the result is the public alternate access mappings (AAM) URLs for all of the Web applications and external resources in your farm are returned. If the url parameter is specified, the result is the public AAM URLs for the Web application that is specified. Note: If the url parameter is used, then the resourcename parameter cannot be used.	URL of the Web application. This parameter should be an existing AAM URL that is assigned to a Web application so that Stsadm can determine which Web application you are targeting. The URL can be a public URL or an internal URL from any zone associated with the targeted Web application.
resourcename	A valid name, such as "Resource1"	No. However, a resource name must already exist before this parameter can be used. You can create a new resource name using the Addzoneurl operation. Note: If the resourcename parameter is used, then the url parameter cannot be used.	Outputs the AAM information for the external resource you specify. This parameter is equivalent to the External Resource Mapping user interface setting that is located on the Create External Resource Mapping page of the SharePoint Central Administration Web site.