EXHIBIT 23.1


                        Consent of Independent Registered Public Accounting Firm


We  hereby  consent  to the  incorporation  by  reference  in this  Registration
Statement  on Form S-8 of our report  dated  December  3, 2004  relating  to the
consolidated  financial  statements  and  financial  statement  schedule,  which
appears in the F5 Networks, Inc.'s Annual Report on Form 10-K for the year ended
September 30, 2004.


/s/ PricewaterhouseCoopers LLP

Seattle, Washington
January 14, 2005