Exhibit 31.2
 CERTIFICATION
OF CHIEF FINANCIAL OFFICER PURSUANT TO EXCHANGE ACT RULES 13A-14(A) AND 15D-14(A), AS
ADOPTED PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT
 I, Steffan Tomlinson, certify that:1.
    
    I have reviewed this Annual Report on Form 10-K of Aruba Networks, Inc.;2.
    
    Based on my knowledge, this report does not contain any untrue
statement of a material fact or omit to state a material fact necessary
to make the statements made, in light of the circumstances under which
such statements were made, not misleading with respect to the period
covered by this report;3.
    
    Based on my knowledge, the financial statements, and other financial
information included in this report, fairly present in all material
respects the financial condition, results of operations and cash flows
of the registrant as of, and for, the periods presented in this report;4.
    
    The registrants other certifying officer(s) and I are responsible for
establishing and maintaining disclosure controls and procedures (as
defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal
control over financial reporting (as defined in Exchange Act Rules
13a-15(f) and 15d-15(f)) for the registrant and have:
 a.
    
    Designed such disclosure controls and
procedures, or caused such disclosure
controls and procedures to be designed under
our supervision, to ensure that material
information relating to the registrant,
including its consolidated subsidiaries, is
made known to us by others within those
entities, particularly during the period in
which this report is being prepared;b.
    
    Designed such internal control over financial
reporting, or caused such internal control
over financial reporting to be designed under
our supervision, to provide reasonable
assurance regarding the reliability of
financial reporting and the preparation of
financial statements for external purposes in
accordance with generally accepted accounting
principles;c.
    
    Evaluated the effectiveness of the
registrants disclosure controls and
procedures and presented in this report our
conclusions about the effectiveness of the
disclosure controls and procedures, as of the
end of the period covered by this report
based on such evaluation; andd.
    
    Disclosed in this report any change in the
registrants internal control over financial
reporting that occurred during the
registrants most recent fiscal quarter (the
registrants fourth fiscal quarter in the
case of an annual report) that has materially
affected, or is reasonably likely to
materially affect, the registrants internal
control over financial reporting; and
 5.
    
    The registrants other certifying officer(s) and I have
disclosed, based on our most recent evaluation of internal
control over financial reporting, to the registrants
auditors and the audit committee of the registrants board of
directors (or persons performing the equivalent functions):
 a.
    
    All significant deficiencies and material weaknesses in the design or
operation of internal control over financial reporting which are
reasonably likely to adversely affect the registrants ability to
record, process, summarize and report financial information; andb.
    
    Any fraud, whether or not material, that involves management or other
employees who have a significant role in the registrants internal
control over financial reporting.
 Date: October 7, 2008
    /s/ Steffan TomlinsonSteffan TomlinsonChief Financial Officer
(Principal Financial Officer)