Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in the Registration Statement (Form S-8) pertaining to the Deterministic Networks, Inc. 2008 Restricted Stock Unit Plan of our reports dated February 25, 2008, with respect to the consolidated financial statements and schedule of Citrix Systems, Inc. included in its Annual Report (Form 10-K) for the year ended December 31, 2007, and the effectiveness of internal control over financial reporting of Citrix Systems, Inc., filed with the Securities and Exchange Commission.

/s/ Ernst & Young LLP

Certified Public Accountants

Fort Lauderdale, Florida

March 24, 2008