An in-band diagnostic tool and method are described herein that are capable of retrieving subscriber information from one or more nodes located within a layer 2 aggregation network. In one application, the diagnostic tool and method can be used by a customer service representative to retrieve subscriber information (e.g., user privileges, current bandwidth usage, available bandwidth) related to a customer that receives television, Internet etc. from an Internet Protocol Television (IPTV) network (which is an application-specific layer 2 aggregation network).