Securities and Exchange Commission
    
                         Washington, D.C.  20549
    
                                  Schedule 13G
    
                Under the Securities Exchange Act of 1934
    
                               (Amendment No. 1)*
    
    December 31, 2011
    (Date of event which requires filing of this statement)
    
    Check the appropriate box to designate the rule pursuant to which
    
    this schedule is filed:
    
      (X) Rule 13d-1(b)
    
      ( ) Rule 13d-1(c)
    
      ( ) Rule 13d-1(d)
    
    
    Name of Issuer: Juniper Networks Inc
    
    Title of Class of Securities: Common
    
    CUSIP Number: 48203R104
    
    
    
    *The remainder of this cover page shall be filled out for a
    
    reporting person's initial filing on this form with respect to
    
    the subject class of securities, and for any subsequent
    
    amendment containing information which would alter the
    
    disclosures provided in a prior cover page.
    
    
    
    The information required in the remainder of this cover page
    
    shall not be deemed to be "filed" for the purpose of Section 18
    
    of the Securities Exchange Act of 1934 ("Act") or otherwise
    
    subject to the liabilities of that section of the Act but shall
    
    be subject to all other provisions of the Act (however, see the
    
    Notes).
    
    
    
    CUSIP Number: 48203R104
    
    1. Name of Reporting Person: Jennison Associates LLC
    
    S.S. or I.R.S. Identification No. of Above Person: IRS
    
    Identification #52-2069785 (formerly 13-2631108)
    
    2. Check the Appropriate Box if a Member of a Group:  Not
    
    Applicable
    
    3. SEC Use Only
    
    4. Citizenship or Place of Organization: Delaware
    
    Number of Shares Beneficially Owned By Each Reporting Person
    
    With:
    
    5. Sole Voting Power: 8,112,994 shares
    
    6. Shared Voting Power: 0 shares
    
    7. Sole Dispositive Power: 0 shares
    
    8. Shared Dispositive Power: 11,327,537 shares
    
    9. Aggregate Amount Beneficially Owned by Each Reporting
    
    Person: 11,327,537 shares
    
    10. Check Box if the Aggregate Amount in Row 9 Excludes
    
    Certain Shares: ( )
    
    11. Percent of Class Represented by Amount in Row 9: 2.2%
    
    12. Type of Reporting Person*: IA
    
    
    
    Item 1(a) Name of Issuer: Juniper Networks Inc
    
    Item 1(b) Address of Issuer's Principal Executive Offices:
    
    1194 North Mathilda Avenue
    Sunnyvale, CA 94089
    
    Item 2(a) Name of Person Filing:  Jennison Associates LLC
    
    Item 2(b) Address of Principal Business Office or Residence:
    
    466 Lexington Avenue
    New York, NY  10017
    
    Item 2(c) Citizenship: Delaware
    
    Item 2(d) Title of Class of Securities: Common
    
    Item 2(e) CUSIP Number: 48203R104
    
    
    
    Item 3 If this statement is filed pursuant to Rules 13d-1(b),
    
    or 13d-2(b), or (c) check whether the person filing is a:
    
    (a) ( ) Broker or Dealer registered under Section 15 of the Act
    
    (b) ( ) Bank as defined in Section 3(a) (6) of the Act
    
    (c) ( ) Insurance Company as defined in Section 3(a) (19) of
    
    the Act
    
    (d) ( ) Investment Company registered under Section 8 of the
    
    Investment Company Act
    
    (e) (X) Investment Adviser in accordance with Section
    
    240.13d-1(b) (1) (ii) (E)
    
    (f) ( ) Employee Benefit Plan, Pension Fund which is subject
    
    to the provision of the Employee Retirement Income Security
    
    Act of 1974 or Endowment Fund in accordance with Section
    
    240.13d-1(b) (ii) (F)
    
    (g) ( ) Parent Holding Company or control person, in accordance
    
    with Section 240.13(b) (ii) (G)
    
    (h) ( ) A savings association as defined by Section 3(b) of the
    
    Federal Deposit Insurance Act
    
    (i)( ) A church plan that is excluded from the definition of an
    
    investment company under Section 3(c) (4) of the Investment Company
    
    Act of 1940.
    
    (j)( ) Group, in accordance with Section 240.13d-1(b) (1) (ii) (J).
    
    If this statement is filed pursuant to Section 240.13d-1(c), check
    
    this box. ( )
    
    
    
    Item 4 Ownership:
    
    Provide the following information regarding the aggregate number
    
    and percentage of the class of securities of the issuer identified
    
    in Item 1.
    
    (a) Amount Beneficially Owned: 11,327,537
    
    (b) Percent of Class: 2.2%
    
    (c) Number of shares as to which the person has:
    
    (i) sole power to vote or to direct the vote: 8,112,994
    
    (ii) shared power to vote or to direct the vote: 0
    
    (iii) sole power to dispose or to direct the disposition of: 0
    
    (iv) shared power to dispose or to direct the disposition of: 11,327,537
    
    
    
    Jennison Associates LLC ("Jennison") furnishes
    
    investment advice to several investment companies,
    
    insurance separate accounts, and institutional clients ("Managed
    
    Portfolios"). As a result of its role as investment adviser of
    
    the Managed Portfolios, Jennison may be deemed to be the
    
    beneficial owner of the shares of the Issuer's Common Stock
    
    held by such Managed Portfolios.  Prudential Financial, Inc.
    
    ("Prudential") indirectly owns 100% of equity interests of
    
    Jennison.  As a result, Prudential may be deemed to have the
    
    power to exercise or to direct the exercise of such voting
    
    and/or dispositive power that Jennison may have with respect to
    
    the Issuer's Common Stock held by the Managed Portfolios.
    
    Jennison does not file jointly with Prudential, as such, shares
    
    of the Issuer's Common Stock reported on Jennison's 13G may be
    
    included in the shares reported on the 13G filed by Prudential.
    
    These shares were acquired in the ordinary course of business,
    
    and not with the purpose or effect of changing or influencing
    
    control of the Issuer.  The filing of this statement should not
    
    be construed as an admission that Jennison is, for the purposes
    
    of Sections 13 or 16 of the Securities Exchange Act of 1934,
    
    the beneficial owner of these shares.
    
    
    
    Item 5 Ownership of Five Percent or Less of a Class:
    
    If this statement is being filed to report the fact that as of
    
    the date hereof the reporting person has ceased to be the
    
    beneficial owner of more than five percent of the securities,
    
    check the following (X).
    
    
    
    Item 6 Ownership of More than Five Percent on Behalf of
    
    Another Person:
    
    Our clients have the right to receive or the power to direct
    
    the receipt of dividends or the profits from the sale of such
    
    securities.  No one client owns more than 5% of such security
    
    class.
    
    
    
    Item 7 Identification and Classification of the Subsidiary
    
    which Acquired the Security being Reported on by the Parent
    
    Holding Company: Not Applicable
    
    
    
    Item 8 Identification and Classification of Members of the
    
    Group: Not Applicable
    
    
    
    Item 9 Notice of Dissolution of Group: Not Applicable
    
    
    
    Item 10 Certification:
    
    By signing below I certify that, to the best of my knowledge
    
    and belief, the securities referred to above were acquired and are
    
    in held the ordinary course of business and were not acquired and
    
    are not held for the purpose of and do not have the effect of
    
    changing or influencing the control of the issuer of the securities
    
    and were not acquired and are not held in connection with or as a
    
    participant in any transaction having that purpose or effect.
    
    After reasonable inquiry and to the best of my knowledge and
    
    belief, I certify that the correct information set forth in
    
    this statement is true, complete and correct.
    
    
    
    February 10, 2011
    
    
    /s/ Janet Early
    Janet Early, Vice President