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* SUMMIT PARTNERS L P (Last) (First) (Middle) 222 BERKELEY STREET 18TH FLOOR (Street) BOSTON MA 02116 (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) Director X 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 06/24/2022
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X 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	06/24/2022		A		10,316(1)	A	$0	8,888,206(2)	I	See Remarks(3)

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

1. Name and Address of Reporting Person* SUMMIT PARTNERS L P (Last) (First) (Middle) 222 BERKELEY STREET 18TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* SUMMIT PARTNERS GE VIII, L.P. (Last) (First) (Middle) 222 BERKELEY STREET, 18TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director 10% Owner Officer (give title below) X Other (specify below) GP of 10% owner

1. Name and Address of Reporting Person* Summit Partners GE VIII, LLC (Last) (First) (Middle) 222 BERKELEY STREET, 18TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director 10% Owner Officer (give title below) X Other (specify below) GP of 10% owner

1. Name and Address of Reporting Person* Summit Investors Management, LLC (Last) (First) (Middle) 222 BERKELEY STREET, 18TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director 10% Owner Officer (give title below) X Other (specify below) Manager of GP of 10% Owner

1. Name and Address of Reporting Person* Summit Partners Growth Equity Fund VIII-A, L.P. (Last) (First) (Middle) 222 BERKELEY STREET, 18TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Summit Partners Growth Equity Fund VIII-B, L.P. (Last) (First) (Middle) 222 BERKELEY STREET, 18TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Summit Investors I, LLC (Last) (First) (Middle) 222 BERKELEY STREET, 18TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Summit Investors I (UK), L.P. (Last) (First) (Middle) 222 BERKELEY STREET, 18TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* SUMMIT MASTER COMPANY, LLC (Last) (First) (Middle) 222 BERKELEY STREET, 18TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director 10% Owner Officer (give title below) X Other (specify below) Manager of Manager of 10% owne

1. Name and Address of Reporting Person* MANNION MARTIN J (Last) (First) (Middle) C/O SUMMIT PARTNERS 222 BERKELEY STREET, 18TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director 10% Owner Officer (give title below) X Other (specify below) Manager of GP of 10% owner

Explanation of Responses:

1. Represents restricted stock units granted to Mr. Chung as part of the director compensation program. The restricted stock units will vest on June 24, 2023, 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.

2. The Common Stock is held as follows: 6,362,818 shares in the name of Summit Partners Growth Equity Fund VIII-A, L.P.; 2,324,553 shares in the name of Summit Partners Growth Equity Fund VIII-B, L.P.; 37,202 shares in the name of Summit Investors I, LLC; 3,273 shares in the name of Summit Investors I (UK), L.P.; 160,360 shares and restricted stock units in the name of Mr. Chung, which are held for the benefit of Summit Partners, L.P.

3. 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 of Summit Partners Growth Equity Fund VIII-A, L.P. and Summit Partners Growth Equity Fund VIII-B, L.P. Summit Master Company, LLC is the managing member 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 GE VIII, LLC, as the general partner of Summit Partners GE VIII, L.P., and Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC has each delegated investment decisions, including voting and dispositive power, to Summit Partners, L.P. and its Investment Committee responsible for voting and investment decisions with respect to the Company. Summit Partners, L.P., through a two-person Investment Committee, responsible for voting and investment decisions with respect to the Issuer, currently composed of Martin J. Mannion and Peter Y. Chung, has voting and dispositive authority over the shares and restricted stock units reported herein and therefore may be deemed to beneficially own such shares. Each of the Summit entities, Mr. Mannion and Mr. Chung each disclaim beneficial ownership of the shares of common stock and the restricted stock units, except to the extent of their respective pecuniary interest therein.

	Summit Partners Growth Equity Fund VIII-B, L.P. By: /s/ Summit Partners Growth Equity Fund VIII-B, L.P., by Summit Partners GE VIII, L.P., its GP, by Summit Partners GE VIII, LLC, its GP, by Adam H. Hennessey, Member	06/28/2022
	Summit Master Company, LLC By: /s/ Summit Master Company, LLC, by Adam H. Hennessey, Member	06/28/2022
	Summit Investors Management, LLC By: /s/ Summit Investors Management, LLC, by Summit Master Company, LLC, its Managing Member, by Adam H. Hennessey, Member	06/28/2022
	Summit Investors I, LLC By: /s/ Summit Investors I, LLC, by Summit Investors Management, LLC, its Manager, by Summit Master Company, LLC, its Managing Member, by Adam H. Hennessey, Member	06/28/2022
	Summit Investors I (UK), L.P. By: /s/ Summit Investors I (UK), L.P., by Summit Investors Management, LLC, its General Partner, by Summit Master Company, LLC, its Managing Member, by Adam H. Hennessey, Member	06/28/2022
	Summit Partners Growth Equity Fund VIII-A, L.P. By: /s/ Summit Partners Growth Equity Fund VIII-A, L.P., by Summit Partners GE VIII, L.P., its GP, by Summit Partners GE VIII, LLC, by Adam H. Hennessey, Member	06/28/2022
	Summit Partners, L.P. By: /s/ Summit Partners, L.P., by Summit Master Company, LLC, its GP, by Adam H. Hennessey, Member	06/28/2022
	Summit Partners GE VIII, LLC By: /s/ Summit Partners GE VIII, LLC, by Summit Partners, L.P., its Manager, by Summit Master Company, LLC, its General Partner, by Adam H. Hennessey, Member	06/28/2022
	Summit Partners GE VIII, L.P. By: /s/ Summit Partners GE VIII, L.P., by Summit Partners GE VIII, LLC, its General Partner, by Summit Partners, L.P., its Manager, by Summit Master Company, LLC, its General Partner, by Adam H. Hennessey, Member	06/28/2022
	Martin J. Mannion By: /s/ Adam H. Hennessey, POA for Martin J. Mannion	06/28/2022
	** Signature of Reporting Person	Date
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