Riverbed Technology (RVBD)

1. BASIS OF PRO FORMA PRESENTATION

The unaudited pro forma condensed combined balance sheets as of September 30, 2008, and the unaudited pro forma condensed combined statements of operations for the nine months ended September 30, 2008, and for the year ended December 31, 2007, are based on the historical financial statements of Riverbed Technology, Inc. and those of Mazu Networks, Inc. after giving effect to the Mazu acquisition on February 19, 2009 and the assumptions, reclassifications and adjustments described in the accompanying notes to the unaudited pro forma condensed combined financial statements.

We account for business combinations pursuant to Financial Accounting Standards Board Statement No. 141 (revised 2007), Business Combinations (SFAS No. 141(R)). In accordance with SFAS No. 141(R), we are required to recognize the assets acquired, the liabilities assumed, measured at their fair values as of the acquisition date. Significant assumptions and estimates have been made in determining the purchase price and the allocation of the purchase price in the unaudited pro forma condensed combined financial statements. These preliminary estimates and assumptions are subject to change during the purchase price measurement period as we finalize the valuations of the net tangible assets, intangible assets and contingent consideration. In particular, the final valuations of identifiable intangible assets, the fair value of the contingent consideration and associated tax effects may change significantly from our preliminary estimates. These changes 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.