1 Filed Pursuant to Rule 424(b)(3) and (c) File Number 333-26163 PROSPECTUS SUPPLEMENT to Prospectus Dated May 9, 1997 172,372 SHARES NETWORK APPLIANCE, INC. COMMON STOCK (NO PAR VALUE PER SHARE) This Prospectus Supplement supplements the Prospectus dated May 9, 1997 (the "Prospectus") of Network Appliance, Inc. (the "Company") relating to the public offering, which is not being underwritten, and sale by certain shareholders of the Company or by pledgees, donees, transferees or other successors in interest that receive such shares as a gift, partnership distribution or other non-sale related transfer (the "Selling Shareholders") of 172,372 shares of Common Stock, no par value, of the Company (the "Common Stock") who received such shares in connection with the acquisition by statutory merger of Internet Middleware Corporation ("IMC"), by and through a merger of IMC with and into the Company. This Prospectus Supplement should be read in conjunction with the Prospectus, and this Prospectus Supplement is qualified by reference to the Prospectus except to the extent that the information herein contained supersedes the information contained in the Prospectus. Capitalized terms used in this Prospectus Summary and not otherwise defined herein have the meanings specified in the Prospectus. SELLING SHAREHOLDERS The following table sets forth the number of shares of Common Stock owned by shareholders of the Company who were not specifically identified in the Prospectus as Selling Shareholders. The table of Selling Shareholders in the Prospectus is hereby amended to include the following shareholders as Selling Shareholders: (1) This Registration Statement shall also cover any additional shares of Common Stock which become issuable in connection with the shares registered for sale hereby by reason of any stock dividend, stock split, recapitalization or other similar transaction effected without the receipt of consideration which results in an increase in the number of the Selling Shareholders' outstanding shares of Common Stock. ------------------
Number of Shares Number of Shares Percent of Registered for Beneficially Outstanding Sale Name of Selling Shareholder Owned Shares Hereby (1) - --------------------------- ----- ------ ---------- Danzig/Thomas Charitable 50,000 * 50,000 Remainder Trust - ----------- * less than one percent