<SEC-DOCUMENT>0001193125-19-248171.txt : 20190918
<SEC-HEADER>0001193125-19-248171.hdr.sgml : 20190918
<ACCEPTANCE-DATETIME>20190918161056
ACCESSION NUMBER:		0001193125-19-248171
CONFORMED SUBMISSION TYPE:	8-K
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20190916
ITEM INFORMATION:		Changes in Registrant's Certifying Accountant
ITEM INFORMATION:		Financial Statements and Exhibits
FILED AS OF DATE:		20190918
DATE AS OF CHANGE:		20190918

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			A10 Networks, Inc.
		CENTRAL INDEX KEY:			0001580808
		STANDARD INDUSTRIAL CLASSIFICATION:	COMPUTER COMMUNICATIONS EQUIPMENT [3576]
		IRS NUMBER:				201446869
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		8-K
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36343
		FILM NUMBER:		191099880

	BUSINESS ADDRESS:	
		STREET 1:		3 WEST PLUMERIA DRIVE
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95134
		BUSINESS PHONE:		(408) 325-8668

	MAIL ADDRESS:	
		STREET 1:		3 WEST PLUMERIA DRIVE
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95134
</SEC-HEADER>
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<TYPE>8-K
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<FILENAME>d804831d8k.htm
<DESCRIPTION>8-K
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 <P STYLE="line-height:1.0pt;margin-top:0pt;margin-bottom:0pt;border-bottom:1px solid #000000">&nbsp;</P>
<P STYLE="line-height:3.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1px solid #000000">&nbsp;</P> <P STYLE="margin-top:4pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>UNITED STATES </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>SECURITIES AND EXCHANGE COMMISSION </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>Washington, D.C. 20549 </B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
<P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>FORM <FONT
STYLE="white-space:nowrap">8-K</FONT> </B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
<P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>CURRENT
REPORT </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>Pursuant to Section&nbsp;13 or 15(d) </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>of the Securities Exchange Act of 1934 </B></P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>Date of report (Date of earliest event reported): September&nbsp;16, 2019 </B></P>
<P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center> <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:24pt; font-family:Times New Roman" ALIGN="center"><B>A10 NETWORKS, INC. </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>(Exact Name of Registrant as Specified in its Charter) </B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
<P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Delaware</B></P></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><FONT STYLE="white-space:nowrap">001-36343</FONT></B></P></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><FONT STYLE="white-space:nowrap">20-1446869</FONT></B></P></TD></TR>
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<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(State or Other Jurisdiction of</B></P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>Incorporation)</B></P></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Commission<BR>File Number)</B></P></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(I.R.S. Employer<BR>Identification No.)</B></P></TD></TR></TABLE>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>3 West Plumeria Drive </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>San Jose, CA 95134 </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Address of Principal Executive Offices, including zip code) </B></P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>(408) <FONT STYLE="white-space:nowrap">325-8668</FONT> </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Registrant&#146;s telephone number including area code) </B></P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Not Applicable </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Former
Name or Address, if Changed Since Last Report) </B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
<P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Check the appropriate box below
if the Form <FONT STYLE="white-space:nowrap">8-K</FONT> filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: </P>
<P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TR style = "page-break-inside:avoid">
<TD WIDTH="4%" VALIGN="top" ALIGN="left">&#9744;</TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) </P></TD></TR></TABLE>
<P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR style = "page-break-inside:avoid">
<TD WIDTH="4%" VALIGN="top" ALIGN="left">&#9744;</TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">Soliciting material pursuant to Rule <FONT STYLE="white-space:nowrap">14a-12</FONT> under the Exchange Act (17
CFR <FONT STYLE="white-space:nowrap">240.14a-12)</FONT> </P></TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR style = "page-break-inside:avoid">
<TD WIDTH="4%" VALIGN="top" ALIGN="left">&#9744;</TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left"><FONT STYLE="white-space:nowrap">Pre-commencement</FONT> communications pursuant to Rule <FONT
STYLE="white-space:nowrap">14d-2(b)</FONT> under the Exchange Act (17 CFR <FONT STYLE="white-space:nowrap">240.14d-2(b))</FONT> </P></TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR style = "page-break-inside:avoid">
<TD WIDTH="4%" VALIGN="top" ALIGN="left">&#9744;</TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left"><FONT STYLE="white-space:nowrap">Pre-commencement</FONT> communications pursuant to Rule <FONT
STYLE="white-space:nowrap">13e-4(c)</FONT> under the Exchange Act (17 CFR <FONT STYLE="white-space:nowrap">240.13e-4(c))</FONT> </P></TD></TR></TABLE>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Securities registered pursuant to Section&nbsp;12(b) of the Act: </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD VALIGN="bottom" WIDTH="1%"></TD>
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<TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>Title of each class</B></P></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom" ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>Trading<BR>Symbol(s)</B></P></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom" ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>Name of each exchange<BR>on which registered</B></P></TD></TR>


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<TD VALIGN="top" ALIGN="center"><B>Common Stock, $0.00001 par value</B></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top" ALIGN="center"><B>ATEN</B></TD>
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<TD VALIGN="top" ALIGN="center"><B>New York Stock Exchange</B></TD></TR>
</TABLE> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of
1933 (&#167;230.405 of this chapter) or Rule <FONT STYLE="white-space:nowrap">12b-2</FONT> of the Securities Exchange Act of 1934 <FONT STYLE="white-space:nowrap">(&#167;240.12b-2</FONT> of this chapter). </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="right">Emerging growth company&nbsp;&nbsp;&#9746; </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">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&nbsp;13(a) of the Exchange
Act.&nbsp;&nbsp;&#9744;</P> <P STYLE="font-size:10pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="line-height:3.0pt;margin-top:0pt;margin-bottom:0pt;border-bottom:1px solid #000000">&nbsp;</P>
<P STYLE="line-height:3.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1px solid #000000">&nbsp;</P>
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<TD WIDTH="10%" VALIGN="top" ALIGN="left"><B>Item&nbsp;4.01.</B></TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left"><B>Changes in Registrant&#146;s Certifying Accountant. </B></P></TD></TR></TABLE>
<P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><I>(a)</I> <I>Dismissal of Independent Registered Public Accounting Firm</I> </P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">On September&nbsp;16, 2019, the Audit Committee of the Board of Directors of A10 Networks, Inc. (the &#147;<B>Company</B>&#148;) dismissed Deloitte&nbsp;&amp;
Touche LLP (&#147;<B>Deloitte</B>&#148;) as the Company&#146;s independent registered public accounting firm. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">The audit reports of Deloitte on the
consolidated financial statements of the Company for each of the two most recent fiscal years ended December&nbsp;31, 2018 and 2017 did not contain an adverse opinion or a disclaimer of opinion and were not qualified or modified as to uncertainty,
audit scope or accounting principles, except that Deloitte&#146;s audit report for the fiscal year ended December&nbsp;31, 2018, which contained an unqualified opinion, included an
<FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">emphasis-of-matter</FONT></FONT> paragraph stating that the Company had changed its method of accounting for revenue from contracts with customers in 2018, due to the adoption of
Accounting Standards Update <FONT STYLE="white-space:nowrap">No.&nbsp;2014-09,</FONT> <I>Revenue from Contracts with Customers (Topic 606)</I>,<I> </I>using the modified retrospective approach. </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">During the Company&#146;s two most recent fiscal years and subsequent interim period from January&nbsp;1, 2019 to September&nbsp;16, 2019, (i) there were no
disagreements with Deloitte on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedures that, if not resolved to Deloitte&#146;s satisfaction, would have caused Deloitte to make reference to
the subject matter of such disagreements in their reports on the Company&#146;s consolidated financial statements for such years, and (ii)&nbsp;there were no &#147;reportable events&#148; as defined in Item 304(a)(1)(v) of Regulation <FONT
STYLE="white-space:nowrap">S-K,</FONT> except as described below. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">As previously disclosed in Item 9A of the Company&#146;s Annual Reports on Form <FONT
STYLE="white-space:nowrap">10-K</FONT> for each of the fiscal years ended December&nbsp;31, 2018 and 2017, the Company concluded that its internal control over financial reporting was not effective as of December&nbsp;31, 2018 and 2017 due to
material weaknesses related to the Company&#146;s control environment and monitoring activities and revenue recognition. The Audit Committee has discussed these matters with Deloitte, and the Company has authorized Deloitte to respond fully to any
inquiries by Armanino concerning these matters. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">The Company provided Deloitte with a copy of the disclosures it is making in this Form <FONT
STYLE="white-space:nowrap">8-K</FONT> and requested that Deloitte furnish the Company with a letter addressed to the Securities and Exchange Commission stating whether or not Deloitte agrees with the statements made herein. A copy of Deloitte&#146;s
letter dated September&nbsp;17, 2019 is filed as Exhibit 16.1 hereto. </P> <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><I>(b)</I> <I>Engagement of Independent Registered Public Accounting Firm</I> </P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">On September&nbsp;16, 2019, following a competitive <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">request-for-proposal</FONT></FONT>
process, the Audit Committee approved the engagement of Armanino LLP (&#147;<B>Armanino</B>&#148;) as the Company&#146;s independent registered public accounting firm for the fiscal year ending December&nbsp;31, 2019. </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">During the Company&#146;s two most recent fiscal years ended December&nbsp;31, 2018 and 2017 and subsequent interim period from January&nbsp;1, 2019 to
September&nbsp;16, 2019, neither the Company nor anyone on its behalf consulted Armanino regarding (i)&nbsp;the application of accounting principles to a specified transaction, either completed or proposed, except as described below, or the type of
audit opinion that might be rendered on the Company&#146;s consolidated financial statements, and neither a written report nor oral advice was provided to the Company that Armanino concluded was an important factor considered by the Company in
reaching a decision as to any accounting, auditing or financial reporting issue, or (ii)&nbsp;any matter that was either the subject of a &#147;disagreement,&#148; as that term is defined in Item 304(a)(1)(iv) of Regulation <FONT
STYLE="white-space:nowrap">S-K,</FONT> or a &#147;reportable event,&#148; as that term is defined in Item 304(a)(1)(v) of Regulation <FONT STYLE="white-space:nowrap">S-K.</FONT> </P>
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 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">During the fiscal year ended December&nbsp;31, 2017, Armanino provided tax services to the Company
consisting of a review of the Company&#146;s quarterly and annual tax provision calculations. In approving the selection of Armanino as the Company&#146;s independent registered public accounting firm, the Audit Committee considered these services
previously provided by Armanino and concluded that such services would not adversely affect the independence of Armanino. </P> <P STYLE="font-size:18pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD WIDTH="10%" VALIGN="top" ALIGN="left"><B>Item&nbsp;9.01</B></TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left"><B>Financial Statements and Exhibits </B></P></TD></TR></TABLE>
<P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(d) Exhibits. </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD VALIGN="bottom" NOWRAP> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; border-bottom:1.00pt solid #000000; display:table-cell; font-size:8pt; font-family:Times New Roman; ">Description</P></TD></TR>


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<TD VALIGN="top" NOWRAP>16.1</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top"><A HREF="d804831dex161.htm">Letter of Deloitte&nbsp;&amp; Touche LLP, dated September&nbsp;17, 2019 </A></TD></TR>
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<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">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
hereunto duly authorized. </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><DIV ALIGN="right">
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<TD VALIGN="top" COLSPAN="3"><B>A10 NETWORKS, INC.</B></TD></TR></TABLE></DIV> <DIV ALIGN="right">
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<TD VALIGN="top">By:</TD>
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<TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman">/s/ Tom Constantino</P></TD></TR>
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<TD VALIGN="top">Name:</TD>
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<TD VALIGN="bottom">Tom Constantino</TD></TR>
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<TD VALIGN="top">Title:</TD>
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<TD VALIGN="bottom">Executive Vice President and Chief Financial Officer</TD></TR>
</TABLE></DIV> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Date: September 18, 2019 </P>
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<TYPE>EX-16.1
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<DESCRIPTION>EX-16.1
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<Center><DIV STYLE="width:8.5in" align="left">
 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="right"><B>Exhibit 16.1 </B></P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">September&nbsp;17, 2019 </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Securities and Exchange Commission
</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">100 F Street, N.E. </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Washington, D.C. 20549-7561 </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Dear Sirs/Madams: </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">We have read Item 4.01 of A10 Networks,
Inc.&#146;s Form <FONT STYLE="white-space:nowrap">8-K</FONT> dated September&nbsp;17, 2019, and have the following comments: </P> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD WIDTH="5%" VALIGN="top" ALIGN="left">1.</TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">We are in agreement with the statements made in paragraphs one through five of Item 4.01(a).
</P></TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD WIDTH="5%" VALIGN="top" ALIGN="left">2.</TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">We have no basis on which to agree or disagree with other statements made therein. </P></TD></TR></TABLE>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Yours truly, </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">/s/ Deloitte&nbsp;&amp; Touche LLP </P>
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