Riverbed Technology (RVBD)

RIVERBED TECHNOLOGY, INC. AND MAZU NETWORKS, INC.

The following unaudited pro forma combined consolidated financial statements are based on the historical financial statements of Riverbed Technology, Inc. and Mazu Networks, Inc. (“Mazu”) after giving effect to Riverbed’s acquisition of Mazu on February 19, 2009, and the assumptions, reclassifications and adjustments described in the accompanying notes to the unaudited pro forma condensed combined financial statements.

The unaudited pro forma condensed combined balance sheet as of September 30, 2008 is presented as if the acquisition of Mazu had occurred on September 30, 2008.

The unaudited pro forma condensed combined statements of operations for the nine months ended September 30, 2008, and year ended December 31, 2007, are presented as if the Mazu acquisition had occurred on January 1, 2007 and were carried forward through each of the aforementioned respective periods.

The allocation of the purchase price used in the unaudited pro forma condensed combined financial statements is based upon preliminary estimates and assumptions. These preliminary estimates and assumptions could change significantly during the purchase price measurement period as we finalize the valuations of the net tangible assets and intangible assets. Any change could result in material variances between our future financial results and the amounts presented in these unaudited condensed combined financial statements, including variances in fair values recorded, as well as expenses and cash flows associated with these items.

The unaudited pro forma condensed combined financial statements are prepared for illustrative purposes only and are not necessarily indicative of or intended to represent the results that would have been achieved had the transaction been consummated as of the dates indicated or that may be achieved in the future. The unaudited pro forma condensed combined financial statements do not reflect any operating efficiencies and associated cost savings that we may achieve with respect to the combined companies.

The unaudited pro forma condensed combined financial statements should be read in conjunction with our historical consolidated financial statements and accompanying notes included in our Annual Report on Form 10-K for the year ended December 31, 2007 and our Quarterly Report on Form 10-Q for the quarter ended September 30, 2008, the historical financial statements of Mazu for the year ended December 31, 2007 included as Exhibit 99.1, the historical financial statements of Mazu as of and for the nine-months ended September 30, 2008 included as Exhibit 99.2, and other information pertaining to us and Mazu contained in this Form 8-K/A.