X0206 3 2014-03-20 0 0001580808 A10 Networks, Inc. ATEN 0000830588 SUMMIT PARTNERS L P 222 BERKELEY STREET 18TH FLOOR BOSTON MA 02116 0 0 0 1 Manager of GP of 10% Owner 0001507545 Summit Investors Management, LLC 222 BERKELEY STREET, 18TH FLOOR BOSTON MA 02116 0 0 0 1 Manager of GP of 10% Owner 0001593029 SUMMIT PARTNERS GE VIII, L.P. 222 BERKELEY STREET, 18TH FLOOR BOSTON MA 02116 0 0 0 1 GP of 10% owner 0001593948 Summit Partners GE VIII, LLC 222 BERKELEY STREET, 18TH FLOOR BOSTON MA 02116 0 0 0 1 GP of 10% owner 0001018067 MANNION MARTIN J C/O SUMMIT PARTNERS 222 BERKELEY STREET, 18TH FLOOR BOSTON MA 02116 0 0 0 1 Manager of GP of 10% owner Series D Redeemable Convertible Preferred Stock Common Stock 9427846 I See Remarks. The Series D Redeemable Convertible Preferred Stock will automatically convert into shares of A10 Networks, Inc.'s (the "Issuer") common stock at a conversion ratio of 117.8481-to-one upon the closing of the Issuer's initial public offering for no additional consideration. The Series D Redeemable Convertible Preferred Stock does not have an expiration date. On an as converted basis, the Series D Redeemable Convertible Preferred Stock is held as follows: 6,873,136 in the name of Summit Partners Growth Equity Fund VIII-A, L.P.; 2,510,989 in the name of Summit Partners Growth Equity Fund VIII-B, L.P., 40,186 in the name of Summit Investors I, LLC; and 3,535 in the name of Summit Investors I (UK), L.P. Summit Partners, L.P. is the managing member of Summit Partners GE VIII, LLC, which is the general partner of Summit Partners GE VIII, L.P., which is the general partner of each Summit Partners Growth Equity Fund VIII-A, L.P. and Summit Partners Growth Equity Fund VIII-B, L.P (ii) the manager of Summit Investors Management, LLC, which is the manager of Summit Investors I, LLC, and the general partner of Summit Investors I (UK), L.P. The entites referred to herein are referred to as the "Summit Entities." Summit Partners, L.P., through a two person investment committee currently composed of Martin J. Mannion and Peter Y. Chung, has voting and dispositive authority over the shares held by each of these entities and therefore beneficially owns such shares. Mr. Mannion and Mr. Chung, as members of the two-person investment committee, have voting and dispositive authority over the shares held by the Summit Entities, and therefore may beneficially own the shares. Each of the Summit Entities, Mr. Mannion and Mr. Chung disclaim beneficial ownership of the shares, and this report shall not be deemed an admission that the Reporting Persons are the beneficial owners of the shares for the purposes of Section 16 or for any other purpose, except, in each case, to the extent of each such Reporting Person's pecuniary interest therein. Summit Partners, L.P., by Summit Master Company, LLC, its General Partner, by Robin W. Devereux, POA for Joseph F. Trustey, Member 2014-03-20 Summit Investors Management, LLC, by Summit Partners, L.P., its Managing Member, by Summit Master Company, LLC, its General Partner, by Robin W. Devereux, POA for Joseph Trustey, Member 2014-03-20 Summit Partners GE VIII, L.P., by Summit Partners GE VIII, LLC, its General Partner, by Summit Partners, L.P., its Manager, by Summit Master Company, LLC, its General Partner, by Robin W. Devereux, POA for Joseph Trustey, Member 2014-03-20 Summit Partners GE VIII, LLC, its General Partner, by Summit Partners, L.P., its Manager, by Summit Master Company, LLC, its General Partner, by Robin W. Devereux, POA for Joseph Trustey, Member 2014-03-20 Robin W. Devereux, POA for Martin J. Mannion 2014-03-20