X0206 3 2014-03-20 0 0001580808 A10 Networks, Inc. ATEN 0001239366 CHUNG PETER Y C/O SUMMIT PARTNERS 222 BERKELEY STREET, 18TH FLOOR BOSTON MA 02116 1 0 0 1 Indirect 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. 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. Chung is a member of the general partner of Summit Partners, L.P. Mr. Chung disclaims beneficial ownership of the shares, and this report shall not be deemed an admission that Mr. Chung is the beneficial owner of the shares for the purposes of Section 16 or for any other purposes, except, in each case, to the extent of Mr. Chung's pecuniary interest therein. Robin W. Devereux, Power of Attorney for Peter Y. Chung 2014-03-20