Abstract: The invention is directed to determining the link integrity using information in a industry standard connection protocol, such as the Peripheral Component Interconnect Express® industry standard system level bus interconnect protocol. One or more features required in the industry standard protocol are used to implement a loopback master and a loopback slave in an interface device (also referred to as an interface) and an external component or device. Using such features may consume less logic area and provide a robust environment for checking link integrity and capabilities.