Ownership Submission
FORM 3
 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
  Lynch Christopher P.
 2. Date of Event Requiring Statement (Month/Day/Year)
09/12/2007		 3. Issuer Name and Ticker or Trading Symbol
F5 NETWORKS INC [FFIV]
(Last)
(First)
(Middle)
C/O F5 NETWORKS, INC., 401 ELLIOTT AVENUE WEST		 4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
SrVP Data Solutions
 5. If Amendment, Date Original Filed(Month/Day/Year)
09/20/2007
(Street)

SEATTLE, WA 98119		 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Beneficially Owned
1.Title of Security
(Instr. 4)		 2. Amount of Securities Beneficially Owned
(Instr. 4)		 3. Ownership Form: Direct (D) or Indirect (I)
(Instr. 5)		 4. Nature of Indirect Beneficial Ownership
(Instr. 5)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 4)		 2. Date Exercisable and Expiration Date
(Month/Day/Year)		 3. Title and Amount of Securities Underlying Derivative Security
(Instr. 4)		 4. Conversion or Exercise Price of Derivative Security 5. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 5)		 6. Nature of Indirect Beneficial Ownership
(Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
Incentive Stock Options (right to buy) 10/01/2007(1) 05/04/2014 Common Stock 658 $ 2.69 D  
Incentive Stock Options (right to buy) 09/20/2007(2) 12/20/2014 Common Stock 6,553 $ 2.99 D  
Incentive Stock Options (right to buy) 10/10/2007(3) 11/10/2015 Common Stock 5,577 $ 2.99 D  

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
Lynch Christopher P.
C/O F5 NETWORKS, INC.
401 ELLIOTT AVENUE WEST
SEATTLE, WA 98119		       SrVP Data Solutions  

Signatures

/s/ Jeffrey A. Christianson by Power of Attorney 11/27/2007
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 5(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) This Incentive Stock Option grant was assumed in the Acopia Networks, Inc acquisition which closed on September 12, 2007, and was converted into an option to acquire F5 Common Stock. This grant vests 25% on October 1, 2007 with the remaining portion of the grant vesting monthly thereafter through January 1, 2008.
(2) This Incentive Stock Option grant was assumed in the Acopia Networks, Inc acquisition which closed on September 12, 2007, and was converted into an option to acquire F5 Common Stock. This grant vests 655 shares on September 20, 2007 with the remaining portion of the grant vesting monthly thereafter through June 20, 2008.
(3) This Incentive Stock Option grant was assumed in the Acopia Networks, Inc acquisition which closed on September 12, 2007, and was converted into an option to acquire F5 Common Stock. This grant vests 278 shares on October 10, 2007 with the remaining portion of the grant vesting monthly thereafter through May 10, 2009.

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