SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* Trivedi Dhrupad (Last) (First) (Middle) C/O A10 NETWORKS, INC. 2300 ORCHARD PARKWAY (Street) SAN JOSE CA 95131 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol A10 Networks, Inc. [ ATEN ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director 10% Owner X Officer (give title below) Other (specify below) Chief Executive Officer
	3. Date of Earliest Transaction (Month/Day/Year) 08/02/2021
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	08/02/2021		M		39,587(1)	A	$0	454,596	D
Common Stock	08/10/2021		M		125,000(2)	A	$0	579,596	D
Common Stock	08/10/2021		S		4,597(3)	D	$13.34	574,999	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Performance-based Restricted Stock Units	(1)	08/02/2021		M			39,587	(1)	02/02/2025	Common Stock	39,587	$0	79,175	D
Performance-based Restricted Stock Units	(2)	08/10/2021		M			125,000	(2)	12/12/2023	Common Stock	125,000	$0	0	D

Explanation of Responses:

1. Performance-Based Restricted Stock Units were previously reported on February 4, 2021, each of which represents a contingent right to receive one share of common stock of ATEN, with vesting subject to the achievement of specified levels of the volume weighted average closing prices of a share of ATEN common stock during any one hundred (100) day trading period between February 2, 2021 and February 2, 2025. The achievement of the first milestone occurred on July 30, 2021, as certified by the compensation committee August 2, 2021, resulting in 39,587 units meeting the appropriate performance-based conditions. However, these shares remain subject to time-based vesting conditions and will therefore vest as to one-third (1/3) on August 9, 2021 and an additional one-third (1/3) on each of the first and second anniversaries of July 30, 2021, subject to continued employment. These shares are reflected on Table I.

2. Performance-Based Restricted Stock Units were previously reported on December 16, 2019, each of which represents a contingent right to receive one share of common stock of ATEN, with vesting subject to the achievement of specified levels of the volume weighted average closing prices of a share of ATEN common stock during any one hundred (100) day trading period between December 12, 2019 and December12, 2023. The last achievement date occurred on August 5, 2021, as certified by the compensation committee of ATEN on August 10, 2021, resulting in 125,000 units meeting the appropriate performance-based conditions. However, these shares remain subject to time-based vesting conditions and will therefore vest as to one-third (1/3) on the first, second and third anniversaries of achievement of the milestone, subject to continued employment. These shares are reflected on Table I.

3. Represents the number of shares automatically sold, on a non-discretionary basis, to cover tax withholding obligations in connection with the vesting of restricted stock units.

Remarks:

	/s/ Robert Cochran, as Attorney-in-Fact	08/12/2021
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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