EXHIBIT 4.1



            CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

         We consent to the reference to our firm under the caption
"Experts-Independent Registered Public Accounting Firm" and to the use of our
report dated September 21, 2011 in the Amendment No. 2 to the Registration
Statement (File No. 333-175817) and related Prospectus of Guggenheim Defined
Portfolios, Series 817.


                                                          /s/ Grant Thornton LLP
                                                              ------------------
                                                              GRANT THORNTON LLP


Chicago, Illinois
September 21, 2011