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 *
  Reinland Andrew
2. Date of Event Requiring Statement (Month/Day/Year)
10/25/2005
3. Issuer Name and Ticker or Trading Symbol
F5 NETWORKS INC [FFIV]
(Last)
(First)
(Middle)
C/O F5 NETWORKS, INC., 401 ELLIOTT AVE. WEST
4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Sr. VP, Chief Finance Officer
5. If Amendment, Date Original Filed(Month/Day/Year)
(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)
Common Stock 3,438
D
 

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
Restricted Stock Units (1) 01/01/2006(2) 07/01/2015 Common Stock 13,125 (3) $ 0 D  
Restricted Stock Units (1) 10/01/2006(4) 09/30/2015 Common Stock 5,000 (3) $ 0 D  
Non-Qualified Stock Option (right to buy) 08/13/2002(5) 08/13/2011 Common Stock 2,709 (6) $ 12.73 D  
Non-Qualified Stock Options (right to buy) 06/08/2003(7) 05/08/2013 Common Stock 3,000 (6) $ 14.64 D  
Non-Qualified Stock Options (right to buy) 08/18/2003(7) 07/18/2013 Common Stock 2,084 (6) $ 17.16 D  
Non-Qualified Stock Options (right to buy) 04/30/2005(8) 04/30/2014 Common Stock 6,000 (6) $ 25.49 D  

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
Reinland Andrew
C/O F5 NETWORKS, INC.
401 ELLIOTT AVE. WEST
SEATTLE, WA 98119
      Sr. VP, Chief Finance Officer  

Signatures

/s/ Andrew Reinland 10/27/2005
**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) Right to receive shares of F5 Networks, Inc. common stock on the vest date.
(2) 15,000 RSUs were granted on 7/1/2005. The RSUs vest quarterly over a 2 year period from the date of grant. 1/1/2006 is the first vest date for the outstanding RSUs.
(3) Indicates the number of RSUs outstanding as of October 25, 2005.
(4) 1/8 of these RSUs will vest on October 1, 2006, with the remainder vesting 1/8 on the first day of the subsequent seven quarters.
(5) Options vest 25% one year following the date of grant and the remaining 75% vest monthly over the following three year period.
(6) Indicates the number of options outstanding as of October 25, 2005.
(7) Options vested in equal monthly increments over the two year period following the date of grant.
(8) Options vested 100% one year following the date of grant.

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