X0306 4 2019-12-04 0 0001580808 A10 Networks, Inc. ATEN 0001358689 SALSBURY PHILLIP J C/O A10 NETWORKS, INC. 3 WEST PLUMERIA DRIVE SAN JOSE CA 95134 1 0 0 0 Common Stock 2019-12-04 4 A 0 23547 0.00 A 176230 D Each share is represented by a Restricted Stock Unit ("RSU"). The RSUs will vest on the earlier of the first anniversary of the grant date or the date of the Issuer's next Annual Meeting, subject to the Reporting Person's continued service as of such date. /s/ Robert Cochran, as Attorney-in-Fact 2019-12-06