EXHIBIT 23.1 CONSENT OF INDEPENDENT AUDITORS We consent to the reference to our firm under the caption "Experts" and to the use of our reports dated March 8, 2000, in the Registration Statement (Form S-4) of Metromedia Fiber Network, Inc. for the registration of 62,500,000 shares of its Class A Common Stock. /s/ Ernst & Young LLP New York, New York November 8, 2000