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                                                                    EXHIBIT 23.1

                         CONSENT OF INDEPENDENT AUDITORS

We consent to the reference to our firm under the caption "Experts" in the
Registration Statement (Form S-3, No. 333-_____) and related Prospectus of
USinternetworking, Inc. for the registration of up to $150,000,000 of its common
stock, and to the incorporation by reference therein of our report dated
January 24, 2000, (except for the Note 21, as to which the date is March 3,
2000), with respect to the consolidated financial statements of
USinternetworking, Inc. included in its Annual Report (Form 10-K) for the year
ended December 31, 1999, filed with the Securities and Exchange Commission.



                                                  /s/ Ernst & Young LLP

Baltimore, Maryland
October 11, 2000