UNITED STATES
 SECURITIES AND EXCHANGE COMMISSION
 Washington, D.C. 20549

 Form 10-K/A
 (Amendment No. 1)

 (Mark One)

 ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

 For the fiscal year ended December 31, 2023
 OR

 TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

 For the transition period from to
 Commission file number: 001-36343

 A10 NETWORKS, INC.
 (Exact Name of Registrant as Specified in its Charter)

 Delaware

 20-1446869

 (State or Other Jurisdiction of
Incorporation or Organization)

 (I.R.S. Employer
Identification No.)

 2300 Orchard Parkway, San Jose, California 95131
 (Address of Principal Executive Offices and Zip Code)

 ( 408) 325-8668
 (Registrant's Telephone Number, Including Area Code)

 Securities registered pursuant to Section 12(b) of the Act:
 Title of Each Class

 Trading Symbol

 Name of Each Exchange on Which Registered

 Common Stock, $.00001 Par Value
 ATEN

 New York Stock Exchange

 Securities registered pursuant to Section 12(g) of the Act:
 None.
 Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes No
 Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes No
 Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes No
 Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes No
 Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule 12b-2 of the Exchange Act.
 Large accelerated filer

 Accelerated filer

 Non-accelerated filer

 Smaller reporting company

 Emerging growth company

 If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.
 Indicate by check mark whether the Registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report.

 If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements.

 Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant's executive officers during the relevant recovery period pursuant to §240.10D-1(b).
 Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes No
 The aggregate market value of the registrant's common stock held by non-affiliates of the registrant as of June 30, 2023 (the last business day of the registrant's most recently completed second fiscal quarter) was approximately $ 1,017.7 million, based upon the closing sale price of such stock on the New York Stock Exchange. Solely for purposes of this disclosure, shares of common stock held by executive officers and directors of the Registrant as of such date, as well as shares held by entities affiliated with our executive officers and directors, have been excluded because such persons may be deemed to be affiliates. This determination of executive officers and directors as affiliates is not necessarily a conclusive determination for any other purposes.
 As of February 16, 2024, the number of outstanding shares of the registrant's common stock, $0.00001 par value per share, was 74,495,333.

 DOCUMENTS INCORPORATED BY REFERENCE

 No documents are incorporated by reference into this Annual Report on Form 10-K/A except those exhibits so incorporated as set forth in the exhibit index.

 Audit Firm ID
 Auditor Name
 Auditor Location

 GRANT THORNTON LLP
 San Jose, California

 EXPLANATORY NOTE

 A10 Networks, Inc. (the "Company") is filing this Amendment Number 1 on Form 10-K/A ("Amendment") to its Annual Report on Form 10-K for the fiscal year ended December 31, 2023, as originally filed with the Securities and Exchange Commission on February 29, 2024 (the "Original Filing"), solely to replace Item 9B. Other Information – Insider Adoption of Termination of Trading Arrangements in the Original Filing.

 This Amendment speaks as of the date of the Original Filing and does not reflect events occurring after the filing of the Original Filing or modify or update disclosures that may be affected by subsequent events. Accordingly, this Amendment should be read in conjunction with the Original Filing and with the Company's filings made with the SEC subsequent to the filing of the Original Filing, including any amendment to those filings.

 Pursuant to Rule 12b-15 under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), this Amendment contains new certifications pursuant to Section 302 of the Sarbanes-Oxley Act of 2002, which are attached hereto. Because no financial statements are contained within this Amendment, paragraphs 3, 4 and 5 of the certifications have been omitted.

 Item 9B. Other Information

 Insider Adoption or Termination of Trading Arrangements

 On October 4, 2023, the trading plan of Dhrupad Trivedi, President, Chief Executive Officer and Chairman, dated June 12, 2023, intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act ("Rule 10b5-1(c)") to sell up to 60,606 shares of our common stock between November 7, 2023 and November 9, 2023, subject to certain conditions, terminated, under which no shares were ultimately sold. Subsequently, on November 27, 2023, Mr. Trivedi adopted a trading plan intended to satisfy Rule 10b5-1(c) with respect to the sale of up to 60,606 shares of our common stock between March 5, 2024 and May 16, 2024 (unless earlier terminated pursuant to the terms of the plan or upon the date all shares under the plan are sold).

 Item 15. Exhibits, Financial Statement Schedules

 1. Financial Statements: The information concerning our financial statements and Report of Independent Registered Public Accounting Firm required by this Item is incorporated by reference in the Original Filing to the section of the Original Filing in Item 8, titled "Financial Statements and Supplementary Data."

 2. Financial Statement Schedules: No schedules are required.

 3. The exhibits listed in the following Index to Exhibits are filed or incorporated by reference as part of this report.

 Exhibit
Number
 Incorporated by Reference

 Description
 Form
 SEC File No.
 Exhibit Number
 Filing Date
 Filed Herewith

 3.1
 Amended and Restated Certificate of Incorporation of the Registrant

 3.1
 December 6, 2019

 3.2
 Amended and Restated Bylaws of the Registrant

 3.2
 December 6, 2019

 4.1
 Form of common stock certificate of the Registrant

 S-1/A
 4.1

 4.2
 Amended and Restated Investors' Rights Agreement among the Registrant and certain holders of its capital stock, amended as of October 4, 2013

 S-1/A
 4.2

 4.3
 Description of the Registrant's securities

 4.3
 March 10, 2020

 10.1*
 Form of Indemnification Agreement between the Registrant and each of its directors and executive officers

 S-1/A
 10.1

 10.2*
 2008 Stock Plan and forms of agreements thereunder

 10.2
 May 13, 2014

 10.3*
 Amended and Restated 2014 Equity Incentive Plan

 10.1
 August 6, 2015

 10.4*
 Amended 2014 Employee Stock Purchase Plan

 10.4
 March 10, 2020

 10.5*
 2014 Employee Stock Purchase Plan and forms of agreements thereunder

 S-1/A
 10.5

 10.6*
 Form of Stock Option Agreement pursuant to the 2008 Stock Plan

 10.2

 10.7*
 Form of Stock Option Agreement- Early Exercise pursuant to the 2008 Stock Plan

 10.3

 10.8*
 Form of Stock Option Agreement pursuant to the Amended and Restated 2014 Equity Incentive Plan

 10.4

 10.9*
 Form of Restricted Stock Unit Agreement pursuant to the Amended and Restated 2014 Equity Incentive Plan

 10.5

 10.10*
 Offer Letter, dated November 12, 2019, by and between the Registrant and Dhrupad Trivedi

 10.2
 November 21, 2019

 10.11*
 Form of CEO Change in Control and Severance Agreement

 10.3
 November 21, 2019

 10.13
 Reseller Agreement, dated April 2, 2009, by and between the Registrant and NEC Corporation

 S-1/A
 10.12

 10.14
 First Amendment to Reseller Agreement, dated May 19, 2011, by and between the Registrant and NEC Corporation

 S-1/A
 10.13

 10.15
 Second Amendment to Reseller Agreement, dated April 1, 2011, by and between the Registrant and NEC Corporation

 S-1/A
 10.14

 10.16
 Third Amendment to Reseller Agreement, dated April 1, 2011, by and between the Registrant and NEC Corporation

 S-1/A
 10.15

 10.17
 Fourth Amendment to Reseller Agreement, dated October 3, 2011, by and between the Registrant and NEC Corporation

 S-1/A
 10.16

 10.18
 Fifth Amendment to Reseller Agreement, dated April 2, 2012, by and between the Registrant and NEC Corporation

 S-1/A
 10.17

 Exhibit
Number
 Incorporated by Reference

 Description
 Form
 SEC File No.
 Exhibit Number
 Filing Date
 Filed Herewith

 10.19
 Sixth Amendment to Reseller Agreement, dated November 29, 2012, by and between the Registrant and NEC Corporation

 S-1/A
 10.18

 10.20
 Seventh Amendment to Reseller Agreement, dated April 9, 2013, by and between the Registrant and NEC Corporation

 S-1/A
 10.19

 10.21
 Eighth Amendment to Reseller Agreement, dated October 22, 2013, by and between the Registrant and NEC Corporation

 S-1/A
 10.2

 10.22
 Ninth Amendment to Reseller Agreement, executed on April 22, 2014, by and between the Registrant and NEC Corporation

 10.1

 10.23
 Manufacturing Services Agreement, dated December 8, 2006, by and between the Registrant and Lanner Electronics (USA)

 S-1/A
 10.21

 10.24
 Amendment No. 1 to Manufacturing Services Agreement, dated June 27, 2013, by and between the Registrant and Lanner Electronics (USA)

 S-1/A
 10.22

 10.25
 Contract Manufacturer Agreement, dated July 1, 2008, by and between the Registrant and AEWIN Technologies, Inc.

 S-1/A
 10.23

 10.26
 Amendment No. 1 to Contract Manufacturer Agreement, dated June 30, 2014, by and between the Registrant and AEWIN Technologies, Inc.

 10.31
 March 11, 2015

 10.27*
 Form of Change in Control and Severance Agreement

 S-1/A
 10.25

 10.28*
 Executive Incentive Compensation Plan

 001-6343
 10.32
 March 1, 2016

 10.29
 Sublease Agreement, dated May 2, 2019, by and between Marvell Corporation and the Registrant

 10.1
 May 8, 2019

 10.30
 Common Stock Repurchase Agreement, dated as of September 8, 2022, between A10 Networks, Inc. and Summit Partners Growth Equity Fund VIII-A, L.P., Summit Partners Growth Equity Fund VIII-B L.P., Summit Investors I, LLC and Summit Investors I (UK), L.P.

 10.1
 September 9, 2022

 21.1
 List of subsidiaries of the Registrant

 21.1
 March 10, 2020

 23.1
 Consent of Grant Thornton LLP, independent registered public accounting firm

 23.1

 23.2
 Consent of Armanino LLP, independent registered public accounting firm

 23.2

 31.1
 Certification of Chief Executive Officer pursuant to Section 302 of the Sarbanes-Oxley Act

 X

 31.2
 Certification of Chief Financial Officer pursuant to Section 302 of the Sarbanes-Oxley Act

 X

 32.1 **
 Certification of Chief Executive Officer pursuant to Section 906 of the Sarbanes-Oxley Act

 32.1

 32.2 **
 Certification of Chief Financial Officer pursuant to Section 906 of the Sarbanes-Oxley Act

 32.2

 A10 Networks, Inc. Policy for the Recovery of Erroneously Awarded Compensation

 X

 101.INS

 101.INS

 101.SCH

 101.SCH

 101.CAL

 101.CAL

 101.DEF

 101.DEF

 101.LAB

 101.LAB

 101.PRE

 101.PRE

 Exhibit
Number
 Incorporated by Reference

 Description
 Form
 SEC File No.
 Exhibit Number
 Filing Date
 Filed Herewith

 X

 * Indicates a management contract or compensatory plan.
 ** The certifications attached as Exhibit 32.1 and 32.2 that accompany this Annual Report on Form 10 K/A are not deemed filed with the Securities and Exchange Commission and are not to be incorporated by reference into any filing of A10 Networks, Inc. under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended, whether made before or after the date of this Annual Report on Form 10 K/A, irrespective of any general incorporation language contained in such filing.

 SIGNATURES

 Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

 A10 NETWORKS, INC.

 Date:
 March 7, 2024
 By:
 /s/ Brian Becker

 Brian Becker

 Chief Financial Officer
(Principal Accounting and Financial Officer)