X0609 4 2026-04-22 0001580808 A10 Networks, Inc. ATEN 0001239366 CHUNG PETER Y false C/O SUMMIT PARTNERS 222 BERKELEY STREET, 18TH FLOOR BOSTON MA 02116 true false false false 0 Common Stock 2026-04-22 4 A 0 7233 0 A 207298 I See Remarks Represents restricted stock units granted to Mr. Chung as part of the director compensation program. The restricted stock units will vest on the earlier of April 22, 2027, or the date of the Issuer's next Annual Meeting, and will settle solely by delivery of an equal number of shares of Common Stock provided that Mr. Chung remains in continuous service with the Issuer through the vesting date. The 207,298 shares and restricted stock units are held in the name of Mr. Chung, which are held for the benefit of Summit Partners, L.P. Mr. Chung holds any Common Stock and restricted stock units for the benefit of Summit Partners, L.P. and Mr. Chung disclaims beneficial ownership of the shares of common stock and the restricted stock units, except to the extent of their pecuniary interest therein. /s/Adam H. Hennessey, POA for Peter Y. Chung 2026-04-24