When a disconnect request fails, the RADIUS dynamic-request server includes an error-cause attribute (RADIUS attribute 101) in the Disconnect-NAK message that it sends back to the RADIUS server. If the detected error does not map to one of the supported error-cause attributes, the router sends the Disconnect-NAK without an error-cause attribute. Table 42 lists the supported error-cause codes.
Table 42: Error-Cause Codes (RADIUS Attribute 101)