Shares A10 NETWORKS, INC. COMMON STOCK $ PAR VALUE PER SHARE UNDERWRITING AGREEMENT

Exhibit 1.1

Shares

A10 NETWORKS, INC.

COMMON STOCK

$ PAR VALUE PER SHARE

UNDERWRITING AGREEMENT

, 2014

▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. LLC

▇▇▇▇▇▇▇ Lynch, Pierce, ▇▇▇▇▇▇ & ▇▇▇▇▇

Incorporated

▇.▇. ▇▇▇▇▇▇ Securities LLC

RBC Capital Markets, LLC

c/o Morgan ▇▇▇▇▇▇▇ & Co. LLC

▇▇▇▇ ▇▇▇▇▇▇▇▇

▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇

Ladies and Gentlemen:

A10 Networks, Inc., a Delaware corporation (the “Company”), proposes to issue and sell to the several Underwriters named in Schedule II hereto (the “Underwriters”), and certain stockholders of the Company (the “Selling Stockholders”) named in Schedule I hereto severally propose to sell to the several Underwriters, an aggregate of shares of the Common Stock, par value $ per share, of the Company (the “Firm Shares”), of which shares are to be issued and sold by the Company and shares are to be sold by the Selling Stockholders, each Selling Stockholder selling the amount set forth opposite such Selling Stockholder’s name in Schedule I hereto.

In addition, the Selling Stockholders propose to sell to the several Underwriters not more than an additional shares of Common Stock, par value $ per share (the “Additional Shares”), if and to the extent that you, as managers of the offering, shall have determined to exercise, on behalf of the Underwriters, the right to purchase such shares of common stock granted to the Underwriters in Section 3 hereof. The Firm Shares and the Additional Shares are hereinafter collectively referred to as the “Shares.” The shares of Common Stock, par value $ per share, of the Company to be outstanding after giving effect to the sales contemplated hereby are hereinafter referred to as the “Common Stock.” The Company and the Selling Stockholders are hereinafter sometimes collectively referred to as the “Sellers.”

The Company has filed with the Securities and Exchange Commission (the “Commission”) a registration statement, including a prospectus, relating to the Shares. The registration statement as amended at the time it becomes effective, including the information (if any) deemed to be part of the registration statement at the time of effectiveness pursuant to Rule 430A under the Securities Act of 1933, as amended (the “Securities Act”), is hereinafter referred to as the “Registration Statement”; the prospectus in the form first used to confirm sales of Shares (or in the form first made available to the Underwriters by the Company to meet requests of purchasers pursuant to Rule 173 under the Securities Act) is hereinafter referred to as the “Prospectus.” If the

Company has filed an abbreviated registration statement to register additional shares of Common Stock pursuant to Rule 462(b) under the Securities Act (the “Rule 462 Registration Statement”), then any reference herein to the term “Registration Statement” shall be deemed to include such Rule 462 Registration Statement.

For purposes of this Agreement, “free writing prospectus” has the meaning set forth in Rule 405 under the Securities Act, “Time of Sale Prospectus” means the preliminary prospectus contained in the Registration Statement at the time of its effectiveness together with the documents, pricing information and the free writing prospectuses, if any, each as set forth in Schedule III hereto, and “broadly available road show” means a “bona fide electronic road show” as defined in Rule 433(h)(5) under the Securities Act that has been made available without restriction to any person. As used herein, the terms “Registration Statement,” “preliminary prospectus,” “Time of Sale Prospectus” and “Prospectus” shall include the documents, if any, incorporated by reference therein as of the date hereof.

1. Representations and Warranties of the Company. The Company represents and warrants to and agrees with each of the Underwriters that:

(a) The Registration Statement has become effective; no stop order suspending the effectiveness of the Registration Statement is in effect, and no proceedings for such purpose are pending before or, to the Company’s knowledge, threatened by the Commission.

(b) (i) The Registration Statement, when it became effective, did not contain and, as amended or supplemented, if applicable, will not contain, as of the date of such amendment or supplement, any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading, (ii) the Registration Statement and the Prospectus comply and, as amended or supplemented, if applicable, will comply in all material respects with the Securities Act and the applicable rules and regulations of the Commission thereunder, (iii) the Time of Sale Prospectus does not, and at the time of each sale of the Shares in connection with the offering when the Prospectus is not yet available to prospective purchasers and at the Closing Date (as defined in Section 5), the Time of Sale Prospectus, as then amended or supplemented by the Company, if applicable, will not, contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, (iv) each broadly available road show, if any, when considered together with the Time of Sale Prospectus, does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading and (v) the Prospectus does not contain and, as amended or supplemented, if applicable, will not contain as of its date or as of the Closing Date any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, except that the representations and

warranties set forth in this paragraph do not apply to statements or omissions in the Registration Statement, the Time of Sale Prospectus or the Prospectus based upon information relating to any Underwriter furnished to the Company in writing by such Underwriter through you expressly for use therein.

(c) The Company is not an “ineligible issuer” in connection with the offering pursuant to Rules 164, 405 and 433 under the Securities Act. Any free writing prospectus that the Company is required to file pursuant to Rule 433(d) under the Securities Act has been, or will be, filed with the Commission in accordance with the requirements of the Securities Act and the applicable rules and regulations of the Commission thereunder. Each free writing prospectus that the Company has filed, or is required to file, pursuant to Rule 433(d) under the Securities Act or that was prepared by or on behalf of or used or referred to by the Company complies or will comply in all material respects with the requirements of the Securities Act and the applicable rules and regulations of the Commission thereunder. Except for the free writing prospectuses, if any, identified in Schedule III hereto, and electronic road shows, if any, each furnished to you before first use, the Company has not prepared, used or referred to, and will not, without your prior consent, prepare, use or refer to, any free writing prospectus.

(d) The Company has been duly incorporated, is validly existing as a corporation in good standing under the laws of the State of Delaware, has the corporate power and authority to own or lease its property and to conduct its business as described in the Time of Sale Prospectus and is duly qualified to transact business and is in good standing in each jurisdiction in which the conduct of its business or its ownership or leasing of property requires such qualification, except to the extent that the failure to be so qualified or be in good standing would not have a material adverse effect on the Company and its subsidiaries, taken as a whole (a “Material Adverse Effect”).

(e) Each significant subsidiary (as such term is defined in Rule 1-02 of Regulation S-X) of the Company has been duly incorporated, is validly existing as a corporation in good standing under the laws of the jurisdiction of its incorporation (to the extent such concepts are applicable under such laws), has the corporate power and authority to own its property and to conduct its business as described in the Time of Sale Prospectus and is duly qualified to transact business and is in good standing in each jurisdiction in which the conduct of its business or its ownership or leasing of property requires such qualification (to the extent such concepts are applicable under such laws), except to the extent that the failure to be so qualified or be in good standing would not reasonably be expected to have a Material Adverse Effect; all of the issued shares of capital stock of each significant subsidiary of the Company have been duly and validly authorized and issued, are fully paid and non-assessable and are owned directly or indirectly by the Company, free and clear of all liens, encumbrances, equities or claims, except to the extent that such liens, encumbrances, equities or claims would not be reasonably likely to have a Material Adverse Effect.

(f) This Agreement has been duly authorized, executed and delivered by the Company.

(g) The authorized capital stock of the Company will conform, as of the Closing Date, as to legal matters to the description thereof contained in each of the Time of Sale Prospectus and the Prospectus.

(h) The shares of Common Stock (including the Shares to be sold by the Selling Stockholders) outstanding prior to the issuance of the Shares to be sold by the Company have been duly authorized and are validly issued, fully paid and non-assessable.

(i) The Shares to be sold by the Company have been duly authorized and, when issued, delivered and paid for in accordance with the terms of this Agreement, will be validly issued, fully paid and non-assessable, and the issuance of such Shares will not be subject to any preemptive or similar rights that have not been validly waived.

(j) The execution and delivery by the Company of, and the performance by the Company of its obligations under, this Agreement will not (i) contravene any provision of applicable law, (ii) violate the terms of the certificate of incorporation or by-laws of the Company, (iii) conflict with or result in a breach of any agreement or other instrument binding upon the Company or any of its subsidiaries that is material to the Company and its subsidiaries or (iv) result in any violation of any judgment, order or decree of any governmental body, agency or court having jurisdiction over the Company or any subsidiary, except that in the case of clauses (i), (iii) and (iv) as would not, individually or in the aggregate, reasonably be expected have a Material Adverse Effect or materially affect the power or ability of the Company to perform its obligations under this Agreement; and no consent, approval, authorization or order of, or qualification with, any governmental body or agency is required to be obtained for the performance by the Company of its obligations under this Agreement, except (i) such as may have previously been obtained, (ii) as may be required by the securities or Blue Sky laws of the various states or foreign jurisdictions or the rules and regulations of the Financial Industry Regulatory Authority, Inc. (“FINRA”) in connection with the offer and sale of the Shares and (iii) for any such consents, approvals, authorizations, orders or qualifications, the absence of which would not, individually or in the aggregate, have a Material Adverse Effect or a material adverse effect on the ability of the Company to perform its obligations under this Agreement or to consummate the transactions contemplated by the Time of Sale Prospectus.

(k) There has not occurred any material adverse change, or any development involving a prospective material adverse change, in the condition, financial or otherwise, or in the earnings, business or operations of the Company and its subsidiaries, taken as a whole, from that set forth in the Time of Sale Prospectus and the Prospectus.

(l) There are no legal or governmental proceedings pending or, to the knowledge of the Company, threatened to which the Company or any of its subsidiaries is a party or to which any of the properties of the Company or any of its subsidiaries is subject (i) other than proceedings accurately described in all material respects in the Time of Sale Prospectus and the Prospectus and proceedings that would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect or materially affect the power or ability of the Company to perform its obligations under this Agreement or to consummate the transactions contemplated by the Time of Sale Prospectus or (ii) that are required to be described in the Registration Statement or the Prospectus and are not so described in all material respects; and there are no statutes, regulations, contracts or other documents to which the Company or its subsidiaries is subject or by which the Company or its subsidiaries is bound that are required to be described in the Registration Statement or the Prospectus or to be filed as exhibits to the Registration Statement that are not described in all material respects or filed as required.

(m) Each preliminary prospectus filed as part of the registration statement as originally filed or as part of any amendment thereto, or filed pursuant to Rule 424 under the Securities Act, complied when so filed in all material respects with the Securities Act and the applicable rules and regulations of the Commission thereunder.

(n) The Company is not, and after giving effect to the offering and sale of the Shares and the application of the proceeds thereof as described in the Prospectus will not be, required to register as an “investment company” as such term is defined in the Investment Company Act of 1940, as amended.

(o) The Company and its subsidiaries (i) are in compliance with any and all applicable foreign, federal, state and local laws and regulations relating to the protection of human health and safety, the environment or hazardous or toxic substances or wastes, pollutants or contaminants (“Environmental Laws”), (ii) have received all permits, licenses or other approvals required of them under applicable Environmental Laws to conduct their respective businesses and (iii) are in compliance with all terms and conditions of any such permit, license or approval, except where such noncompliance with Environmental Laws, failure to receive required permits, licenses or other approvals or failure to comply with the terms and conditions of such permits, licenses or approvals would not, singly or in the aggregate, be reasonably expected to have a Material Adverse Effect.

(p) There are no costs or liabilities associated with Environmental Laws (including, without limitation, any capital or operating expenditures required for clean-up, closure of properties or compliance with Environmental Laws or any permit, license or approval, any related constraints on operating activities and any potential liabilities to third parties) which would, singly or in the aggregate, be reasonably expected to have a Material Adverse Effect.

(q) There are no contracts, agreements or understandings between the Company and any person granting such person the right to require the Company to file a registration statement under the Securities Act with respect to any securities of the Company or to require the Company to include such securities with the Shares registered pursuant to the Registration Statement, except as otherwise have been validly waived in connection with the issuance and sale of the Shares contemplated hereby and as have been described in the Time of Sale Prospectus and the Prospectus.

(r) Except as described in the Time of Sale Prospectus, the Registration Statement and the Prospectus, neither the Company nor any officer, director, subsidiary, or controlled affiliates, nor to the Company’s knowledge, any agent, distributor, or representative of the Company or of any of its subsidiaries or controlled affiliates has any reason to believe that the Company or any of the foregoing persons or entities have taken any action in violation of, or which may cause the Company or any of its subsidiaries to be in violation of, any applicable U.S. law governing imports into or exports from the United States in connection with the Company’s products, including without limitation: any executive orders or regulations issued with respect to the laws referred to in this Section 1(r), the Arms Export Control Act (22 U.S.C.A. § 2278), the Export Administration Act (50 U.S.C. App. §§ 2401-2420), the International Traffic in Arms Regulations (22 CFR 120-130), the Export Administration Regulations (15 CFR 730 et seq.), the Customs Laws of the United States (19 U.S.C. § 1 et seq.), the International Emergency Economic Powers Act (50 U.S.C. § 1701-1706), any other export control regulations issued by the agencies listed in Part 730 of the Export Administration Regulations, or any applicable non-U.S. laws of a similar nature, except non-compliances which would not, individually or in the aggregate, be reasonably expected to have a Material Adverse Effect. Except as described in the Time of Sale Prospectus, the Registration Statement and the Prospectus, there has never been a claim or change made, investigation undertaken, violation found, or settlement of any enforcement action under any of the laws referred to in this Section 1(r) by any governmental entity with respect to matters arising under such laws against the Company, its subsidiaries or, to the Company’s knowledge, against the agents, distributors, or representative of any of the foregoing in connection with their relationship with the Company. The Company maintains a compliance program appropriate to the requirements of the aforementioned laws.

(s) Neither the Company nor any of its subsidiaries or controlled affiliates, nor any director or officer of the Company, nor, to the Company’s knowledge, any employee, agent or representative of the Company or of any of its subsidiaries or controlled affiliates acting on behalf of the Company or any of its subsidiaries or controlled affiliates, has taken or will take any action in furtherance of an offer, payment, promise to pay, or authorization or approval of the payment or giving of money, property, gifts or anything else of value, directly or indirectly, to any “government official” (including any officer or employee of a government or government-owned or controlled entity or of a public international organization, or any person acting in an official capacity for or on behalf of any of

the foregoing, or any political party or party official or candidate for political office) to illegally influence official action or secure an improper advantage for the Company or its subsidiaries; and the Company and its subsidiaries and controlled affiliates have conducted their businesses in compliance with applicable anti-corruption laws and have instituted and are maintaining (and have no present or currently foreseeable intent to discontinue) policies and procedures designed to promote and achieve compliance with such laws.

(t) The operations of the Company and its subsidiaries are and have been conducted at all times in material compliance with all applicable financial recordkeeping and reporting requirements, including those of the Bank Secrecy Act, as amended by Title III of the Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism Act of 2001 (USA PATRIOT Act), and the applicable anti-money laundering statutes of jurisdictions where the Company and its subsidiaries conduct business, the rules and regulations thereunder and any related or similar rules, regulations or guidelines, issued, administered or enforced by any governmental agency (collectively, the “Anti-Money Laundering Laws”), and no action, suit or proceeding by or before any court or governmental agency, authority or body or any arbitrator involving the Company or any of its subsidiaries with respect to the Anti-Money Laundering Laws is pending or, to the knowledge of the Company, threatened.

(u) (i) Neither the Company nor any of its subsidiaries, nor any director or officer thereof, nor, to the Company’s knowledge, any employee, agent, controlled affiliate or representative of the Company or any of its subsidiaries, is an individual or entity (“Person”) that is, or is owned or controlled by a Person that is:

(A) the subject of any sanctions administered or enforced by the U.S. Department of Treasury’s Office of Foreign Assets Control (“OFAC”), the United Nations Security Council (“UNSC”), the European Union (“EU”), Her Majesty’s Treasury (“HMT”), or other relevant sanctions authority (collectively, “Sanctions”), nor

(B) located, organized or resident in a country or territory that is the subject of Sanctions (including, without limitation, Cuba, Iran, North Korea, Sudan and Syria).

(ii) The Company will not, directly or indirectly, use the proceeds of the offering, or lend, contribute or otherwise make available such proceeds to any subsidiary, joint venture partner or other Person:

(A) to fund or facilitate any activities or business of or with any Person or in any country or territory that, at the time of such funding or facilitation, is the subject of Sanctions; or

(B) in any other manner that will result in a violation of Sanctions by any Person (including any Person participating in the offering, whether as underwriter, advisor, investor or otherwise).

(C) For the past 5 years, the Company and its subsidiaries have not knowingly engaged in, are not now knowingly engaged in, and will not engage in, any dealings or transactions with any Person, or in any country or territory, that at the time of the dealing or transaction is or was the subject of Sanctions.

(v) Subsequent to the respective dates as of which information is given in each of the Registration Statement, the Time of Sale Prospectus and the Prospectus, and except as disclosed in the Time of Sale Prospectus and the Prospectus, (i) the Company and its subsidiaries have not incurred any material liability or obligation, direct or contingent, nor entered into any material transaction; (ii) the Company has not purchased any of its outstanding capital stock other than from its employees or other service providers in connection with the termination of their service, nor declared, paid or otherwise made any dividend or distribution of any kind on its capital stock other than ordinary and customary dividends; and (iii) there has not been any material change in the capital stock, short-term debt or long-term debt of the Company and its subsidiaries, taken as a whole, except in each case as described in each of the Registration Statement, the Time of Sale Prospectus and the Prospectus, respectively.

(w) The Company and its subsidiaries do not own any real property. The Company and its subsidiaries have good and marketable title to all personal property (other than intellectual property, which is covered by Section 1(x)) owned by them which is material to the business of the Company and its subsidiaries, taken as a whole, in each case free and clear of all liens, encumbrances and defects, except such as are described in the Time of Sale Prospectus and the Prospectus or such as do not materially diminish the value of such property and do not materially interfere with the use made and proposed to be made of such property by the Company and its subsidiaries, taken as whole; and any real property and buildings held under lease by the Company and its subsidiaries are held by them under valid, subsisting and, to the Company’s knowledge, enforceable leases with such exceptions as are not material and do not materially interfere with the use made and proposed to be made of such property and buildings by the Company and its subsidiaries, taken as a whole, in each case except as described in the Time of Sale Prospectus and the Prospectus.

(x) The Company and its subsidiaries, taken as a whole, own, possess or have the valid right to use, or can acquire on commercially reasonable terms, all material patents, patent rights, licenses, inventions, copyrights, know-how (including trade secrets and other unpatented and/or unpatentable proprietary or confidential information, systems or procedures), trademarks, service marks and trade names currently employed by them in connection with the business now

conducted by them (the “Company Intellectual Property”). Except as disclosed in the Time of Sale Prospectus, the Registration Statement and the Prospectus, or as would not, individually or in the aggregate, be reasonably expected to have a Material Adverse Effect, (i) to the Company’s knowledge, there are no third parties who have been able to establish any material rights to any Company Intellectual Property, except for the retained rights of the owners of the Company Intellectual Property that is licensed to the Company; (ii) there is no pending or, to the Company’s knowledge, threatened action, suit, proceeding or claim by others challenging the Company’s rights or any of its subsidiaries’ rights in or to any Company Intellectual Property and neither the Company nor any of its subsidiaries is aware of any facts that could form a reasonable basis for any such actions, suits, proceedings or claims; and (iii) there is no pending or, to the Company’s knowledge, threatened action, suit, proceeding or claim by others that the Company or any of its subsidiaries infringes or misappropriates any intellectual property or other proprietary rights of others, and neither the Company nor any of its subsidiaries is aware of any facts which would form a reasonable basis for any such action, suit, proceeding or claim.

(y) No material labor dispute with the employees of the Company or any of its subsidiaries exists, except as described in the Time of Sale Prospectus and the Prospectus, or, to the knowledge of the Company, is imminent; and the Company is not aware of any existing, threatened or imminent labor disturbance by the employees of any of its principal suppliers, manufacturers or contractors that would reasonably be expected to have a Material Adverse Effect.

(z) The Company and each of its subsidiaries, taken a whole, are insured by insurers of recognized financial responsibility against such losses and risks and in such amounts as are, in the Company’s reasonable judgment, prudent and customary in the businesses in which they are engaged; neither the Company nor any of its subsidiaries has been refused any insurance coverage sought or applied for; and neither the Company nor any of its subsidiaries has any reason to believe that it will not be able to renew its existing insurance coverage as and when such coverage expires or to obtain similar coverage from similar insurers as may be necessary to continue its business at a cost that would not reasonably be expected to have a Material Adverse Effect, except as described in the Time of Sale Prospectus and the Prospectus.

(aa) The Company and its subsidiaries possess all certificates, authorizations and permits issued by the appropriate federal, state or foreign regulatory authorities necessary to conduct their respective businesses except where the failure to obtain such certificates, authorizations or permits would not, individually or in the aggregate, be reasonably expected to have a Material Adverse Effect, and neither the Company nor any of its subsidiaries has received any written notice of proceedings relating to the revocation or modification of any such certificate, authorization or permit which, singly or in the aggregate, if the subject of an unfavorable decision, ruling or finding, would reasonably be expected to have a Material Adverse Effect, except as described in the Time of Sale Prospectus.

(bb) The Company and its subsidiaries, taken as a whole, maintain a system of internal accounting controls over financial reporting sufficient to provide reasonable assurance that (i) transactions are executed in accordance with management’s general or specific authorizations; (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with generally accepted accounting principles as applied in the United States (“U.S. GAAP”) and to maintain asset accountability; (iii) access to assets is permitted only in accordance with management’s general or specific authorization; and (iv) the amounts reflected on the Company’s balance sheet for assets are compared with the existing assets at reasonable intervals and appropriate action is taken with respect to any differences. Except as described in the Time of Sale Prospectus, since the end of the Company’s most recent fiscal year for which audited financial statements are available, there has been (i) no material weakness in the Company’s internal control over financial reporting (whether or not remediated) and (ii) no change in the Company’s internal control over financial reporting that has materially and adversely affected, or is reasonably likely to materially and adversely affect, the Company’s internal control over financial reporting.

(cc) The financial statements of the Company filed with the Commission as a part of the Registration Statement and included in the Time of Sale Prospectus and the Prospectus present fairly the financial position of the Company as of the dates indicated and the results of its operations and cash flows for the periods specified. Such financial statements have been prepared in conformity with U.S. GAAP applied on a consistent basis throughout the periods involved. To the Company’s knowledge, Deloitte & Touche LLP is an independent public accounting firm within the meaning of the Securities Act and the rules and regulations promulgated thereunder.

(dd) The Company maintains disclosure controls and procedures that comply with the requirements of the Exchange Act; such disclosure controls and procedures have been designed to ensure that material information relating to the Company and its subsidiaries is made known to the Company’s principal executive officer and principal financial officer by others within those entities; and such disclosure controls and procedures are effective.

(ee) Except as described in the Time of Sale Prospectus and the Registration Statement, the Company has not sold, issued or distributed any shares of Common Stock during the six-month period preceding the date hereof, including any sales pursuant to Rule 144A under, or Regulation D or S of, the Securities Act, other than shares issued pursuant to employee benefit plans, qualified stock option plans or other employee compensation plans or pursuant to outstanding options, rights or warrants.

(ff) The Company and each of its subsidiaries have filed all federal, state, local and foreign tax returns required to be filed through the date of this Agreement or have requested extensions thereof (except where the failure to file would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect) and have paid all taxes required to be paid thereon (except for cases in which the failure to file or pay would not reasonably be expected to have a Material Adverse Effect, or, except as currently being contested in good faith and for which reserves required by U.S. GAAP have been created in the financial statements of the Company), and no tax deficiency has been determined adversely to the Company or any of its subsidiaries which has had (nor does the Company nor any of its subsidiaries have any notice or knowledge of any tax deficiency which could reasonably be expected to be determined adversely to the Company or its subsidiaries and which could reasonably be expected to have) a Material Adverse Effect.

(gg) From the time of initial confidential submission of the Registration Statement to the Commission (or, if earlier, the first date on which the Company engaged directly or through any person authorized to act on its behalf in any Testing-the-Waters Communication) through the date hereof, the Company has been and is an “emerging growth company,” as defined in Section 2(a) of the Securities Act (an “Emerging Growth Company”). “Testing-the-Waters Communication” means any oral or written communication with potential investors undertaken in reliance on Section 5(d) of the Securities Act.

(hh) The Company (i) has not alone engaged in any Testing-the-Waters Communication other than Testing-the-Waters Communications with the consent of ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. LLC with entities that are qualified institutional buyers within the meaning of Rule 144A under the Securities Act or institutions that are accredited investors within the meaning of Rule 501 under the Securities Act and (ii) has not authorized anyone other than ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. LLC, ▇▇▇▇▇▇▇ Lynch, Pierce, ▇▇▇▇▇▇ & ▇▇▇▇▇ Incorporated and ▇.▇. ▇▇▇▇▇▇ Securities LLC to engage in Testing-the-Waters Communications. The Company reconfirms that ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. LLC, ▇▇▇▇▇▇▇ Lynch, Pierce, ▇▇▇▇▇▇ & ▇▇▇▇▇ Incorporated and ▇.▇. ▇▇▇▇▇▇ Securities LLC have each been authorized to act on its behalf in undertaking Testing-the-Waters Communications, if any. The Company has not distributed any Written Testing-the-Waters Communications other than those listed on Schedule IV hereto. “Written Testing-the-Waters Communication” means any Testing-the-Waters Communication that is a written communication within the meaning of Rule 405 under the Securities Act.

(ii) As of the time of each sale of the Shares in connection with the offering when the Prospectus is not yet available to prospective purchasers, none of (A) the Time of Sale Prospectus, (B) any free writing prospectus, when considered together with the Time of Sale Prospectus, and (C) any individual Written Testing-the-Waters Communication, when considered together with the Time of Sale Prospectus, included, includes or will include an untrue statement of a material fact or omitted, omits or will omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading.

2. Representations and Warranties of the Selling Stockholders. Each Selling Stockholder, solely with respect to itself and not as to any other Selling Stockholder, represents and warrants to and agrees with each of the Underwriters that:

(a) This Agreement has been duly authorized, executed and delivered by or on behalf of such Selling Stockholder.

(b) The execution and delivery by such Selling Stockholder of, and the performance by such Selling Stockholder of its obligations under, this Agreement, the Custody Agreement signed by such Selling Stockholder and , as Custodian, relating to the deposit of the Shares to be sold by such Selling Stockholder (the “Custody Agreement”) and the Power of Attorney appointing certain individuals as such Selling Stockholder’s attorneys-in-fact to the extent set forth therein, relating to the transactions contemplated hereby and by the Registration Statement (the “Power of Attorney”) will not contravene (i) any provision of applicable law, (ii) the certificate of incorporation or by-laws of such Selling Stockholder (if such Selling Stockholder is a corporation), (iii) any agreement or other instrument binding upon such Selling Stockholder, (iv) the constituent documents of such Selling Stockholder (if such Selling Stockholder is not a natural person or a corporation) or (v) any judgment, order or decree of any governmental body, agency or court having jurisdiction over such Selling Stockholder, except in the cases of (i) and (iii) above, for such contraventions as would not reasonably be expected to have a material adverse effect on the ability of such Selling Stockholder to perform its obligations hereunder, or under the Custody Agreement or the Power of Attorney. No consent, approval, authorization or order of, or qualification with, any governmental body or agency is required for the performance by such Selling Stockholder of its obligations under this Agreement or the Custody Agreement or Power of Attorney of such Selling Stockholder, except such as have been obtained and made under the Securities Act and such as may be required by the Exchange Act or the rules and regulations thereunder or the securities or Blue Sky laws of the various states or foreign jurisdictions in connection with the offer and sale of the Shares.

(c) With respect to the Shares to be sold by such Selling Stockholder that are outstanding on the date hereof, such Selling Stockholder has and will have on the Closing Date, and with respect to such Shares to be sold upon exercise of options on the Closing Date will have on the Closing Date, valid title to, or a valid “security entitlement” within the meaning of Section 8-501 of the New York Uniform Commercial Code in respect of, the Shares to be sold by such Selling Stockholder free and clear of all security interests, claims, liens, equities or other encumbrances (other than those created by the Custody Agreement and Power of Attorney) and the legal right and power, and all authorization and approval required by law, to enter into this Agreement, the Custody Agreement and the Power of Attorney and to sell, transfer and deliver the Shares to be sold by such Selling Stockholder or a security entitlement in respect of such Shares.

(d) The Custody Agreement and the Power of Attorney have been duly authorized, executed and delivered by such Selling Stockholder and are valid and binding agreements of such Selling Stockholder, except as limited by laws of general application relating to bankruptcy, insolvency and the relief of debtors and as limited by rules of law governing specific performance, injunctive relief or other equitable remedies and by general principles of equity.

(e) Upon payment for the Shares to be sold by such Selling Stockholder pursuant to this Agreement, delivery of such Shares, as directed by the Underwriters, to Cede & Co. (“Cede”) or such other nominee as may be designated by the Depository Trust Company (“DTC”), registration of such Shares in the name of Cede or such other nominee and the crediting of such Shares on the books of DTC to securities accounts of the Underwriters (assuming that neither DTC nor any such Underwriter has notice of any adverse claim (within the meaning of Section 8-105 of the New York Uniform Commercial Code (the “UCC”)) to such Shares), (A) DTC shall be a “protected purchaser” of such Shares within the meaning of Section 8-303 of the UCC, (B) under Section 8-501 of the UCC, the Underwriters will acquire a valid security entitlement in respect of such Shares and (C) no action based on any “adverse claim”, within the meaning of Section 8-102 of the UCC, to such Shares may be validly asserted against the Underwriters with respect to such security entitlement; for purposes of this representation, such Selling Stockholder may assume that when such payment, delivery and crediting occur, (x) such Shares will have been registered in the name of Cede or another nominee designated by DTC, in each case on the Company’s share registry in accordance with its certificate of incorporation, bylaws and applicable law, (y) DTC will be registered as a “clearing corporation” within the meaning of Section 8-102 of the UCC and (z) appropriate entries to the accounts of the several Underwriters on the records of DTC will have been made pursuant to the UCC.

(f) Such Selling Stockholder is not prompted by any material information concerning the Company or its subsidiaries which is not set forth in the Time of Sale Prospectus to sell its Shares pursuant to this Agreement.

(g) (i) The Registration Statement, when it became effective, did not contain and, as amended or supplemented, if applicable, will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading, (ii) the Time of Sale Prospectus does not, and at the time of each sale of the Shares in connection with the offering when the Prospectus is not yet available to prospective purchasers and at the Closing Date (as defined in Section 5), the Time of Sale Prospectus, as then amended or supplemented by the Company, if applicable, will not, contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the

circumstances under which they were made, not misleading, (iii) each broadly available road show, if any, when considered together with the Time of Sale Prospectus, does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading and (iv) the Prospectus does not contain and, as amended or supplemented, if applicable, will not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, provided that such Selling Stockholder makes no representation and warranty with respect to any statements or omissions made in reliance upon and in conformity with information relating to any Underwriter furnished to the Company in writing by such Underwriter through you expressly for use in such Registration Statement, Time of Sale Prospectus or Prospectus; provided further that, the representations and warranties set forth in this paragraph 2(g) are limited in all respects to statements or omissions made in reliance upon information relating to such Selling Stockholder furnished to the Company in writing by such Selling Stockholder expressly for use in the Registration Statement, the Time of Sale Prospectus, any broadly available road show, or the Prospectus or any amendments or supplements thereto it being understood and agreed that the only information furnished by such Selling Stockholder consists of the name of such Selling Stockholder the number of offered shares and the address and other information with respect to such Selling Stockholder (excluding percentages) that appear in the table (and corresponding footnotes) under the caption “Principal and Selling Stockholders” in the Prospectus (“Selling Stockholder Information”).

3. Agreements to Sell and Purchase. Each Seller, severally and not jointly, hereby agrees to sell to the several Underwriters, and each Underwriter, upon the basis of the representations and warranties herein contained, but subject to the conditions hereinafter stated, agrees, severally and not jointly, to purchase from such Seller at $ a share (the “Purchase Price”) the number of Firm Shares (subject to such adjustments to eliminate fractional shares as you may determine) that bears the same proportion to the number of Firm Shares to be sold by such Seller as the number of Firm Shares set forth in Schedule II hereto opposite the name of such Underwriter bears to the total number of Firm Shares.

On the basis of the representations and warranties contained in this Agreement, and subject to its terms and conditions, the Selling Stockholders, severally and not jointly, hereby agree to sell to the Underwriters the Additional Shares, and the Underwriters shall have the right to purchase, severally and not jointly, at the Purchase Price up to Additional Shares (subject to such adjustments to eliminate fractional shares as you may determine) that bears the same proportion to the number of Firm Shares as the number of Firm Shares set forth in Schedule II hereto opposite the name of such Underwriter bears to the total number of Firm Shares, provided, however, that the amount paid by the Underwriters for any Additional Shares shall be reduced by an amount per share equal to any dividends declared by the Company and payable on the Firm Shares but not payable on such Additional Shares. You may

exercise this right on behalf of the Underwriters in whole or from time to time in part by giving written notice not later than 30 days after the date of this Agreement. Any exercise notice shall specify the number of Additional Shares to be purchased by the Underwriters and the date on which such shares are to be purchased. Each purchase date must be at least one business day after the written notice is given and may not be earlier than the closing date for the Firm Shares nor later than ten business days after the date of such notice. Additional Shares may be purchased as provided in Section 5 hereof solely for the purpose of covering over-allotments made in connection with the offering of the Firm Shares. On each day, if any, that Additional Shares are to be purchased (an “Option Closing Date”), each Underwriter agrees, severally and not jointly, to purchase the number of Additional Shares (subject to such adjustments to eliminate fractional shares as you may determine) that bears the same proportion to the total number of Additional Shares to be purchased on such Option Closing Date as the number of Firm Shares set forth in Schedule II hereto opposite the name of such Underwriter bears to the total number of Firm Shares.

The Company hereby agrees that, without the prior written consent of ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. LLC on behalf of the Underwriters, it will not, during the period ending 180 days after the date of the Prospectus (the “Restricted Period”), (1) offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, lend, or otherwise transfer or dispose of, directly or indirectly, any shares of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock or (2) enter into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of the Common Stock, whether any such transaction described in clause (1) or (2) above is to be settled by delivery of Common Stock or such other securities, in cash or otherwise or (3) file any registration statement with the Commission relating to the offering of any shares of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock.

The restrictions contained in the preceding paragraph shall not apply to (a) the Shares to be sold hereunder, (b) the issuance by the Company of shares of Common Stock upon the exercise of an option or warrant or the conversion of a security outstanding on the date hereof of which the Underwriters have been advised in writing, (c) the grant of options to purchase or the issuance of shares of Common Stock by the Company to employees, officers, directors, advisors or consultants of the Company pursuant to employee benefit plans in effect on the date hereof and described in the Time of Sale Prospectus and Prospectus or pursuant to an employee stock purchase plan described in the Time of Sale Prospectus and Prospectus, (d) the establishment of a trading plan pursuant to Rule 10b5-1 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), for the transfer of shares of Common Stock, provided that such plan does not provide for the transfer of Common Stock during the Restricted Period and no public announcement or filing under the Exchange Act regarding the establishment of such plan shall be required of or voluntarily made by or on behalf of the Company, (e) the sale or issuance of or entry into an agreement to sell or issue shares of Common Stock or securities convertible into or exercisable for Common Stock in connection with any (i) mergers, (ii) acquisition of securities, businesses, property.

technologies or other assets, (iii) joint ventures, (iv) strategic alliances, commercial relationships or other collaborations, (v) equipment leasing arrangements, (vi) debt financing or (vii) the assumption of employee benefit plans in connection with mergers or acquisitions; provided, that the aggregate number of shares of Common Stock or securities convertible into or exercisable for Common Stock (on an as-converted or as-exercised basis, as the case may be) that the Company may sell or issue or agree to sell or issue pursuant to this clause (e) shall not exceed 5% of the total number of shares of the Company’s Common Stock issued and outstanding immediately following the completion of the transactions contemplated by this Agreement (determined on a fully-diluted basis and as adjusted for stock splits, stock dividends and other similar events after the date hereof); and provided further, that each recipient of shares of Common Stock or securities convertible into or exercisable for Common Stock pursuant to this clause (e) shall, on or prior to such issuance, execute a lock-up agreement substantially in the form of Exhibit A hereto with respect to the remaining portion of the Restricted Period, or (f) the filing of one or more registration statements on Form S-8 with the Commission with respect to shares of Common Stock issued or issuable under any equity compensation plan in effect on the date hereof.

If ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. LLC in its sole discretion, agrees to release or waive the restrictions set forth in a lock-up letter described in Section 6(g) hereof for an officer or director of the Company and provides the Company with notice of the impending release or waiver at least three business days before the effective date of the release or waiver, the Company agrees to announce the impending release or waiver by (i) a press release substantially in the form of Exhibit B hereto through a major news service or (ii) any other method that satisfies the obligations described in FINRA Rule 5131(d)(2) at least two business days before the effective date of the release or waiver.

4. Terms of Public Offering. The Sellers are advised by you that the Underwriters propose to make a public offering of their respective portions of the Shares as soon after the Registration Statement and this Agreement have become effective as in your judgment is advisable. The Sellers are further advised by you that the Shares are to be offered to the public initially at $ a share (the “Public Offering Price”) and to certain dealers selected by you at a price that represents a concession not in excess of $ a share under the Public Offering Price, and that any Underwriter may allow, and such dealers may reallow, a concession, not in excess of $ a share, to any Underwriter or to certain other dealers.

5. Payment and Delivery. Payment for the Firm Shares to be sold by each Seller shall be made to such Seller in Federal or other funds immediately available in New York City against delivery of such Firm Shares for the respective accounts of the several Underwriters at 10:00 a.m., New York City time, on , 20 , or at such other time on the same or such other date, not later than , 20 , as shall be designated in writing by you. The time and date of such payment are hereinafter referred to as the “Closing Date.” The Closing Date and each Option Closing Date are each sometimes referred to herein as an “Applicable Closing Date.”

Payment for any Additional Shares shall be made to the Selling Stockholders in Federal or other funds immediately available in New York City against delivery of such Additional Shares for the respective accounts of the several Underwriters at 10:00 a.m., New York City time, on the date specified in the corresponding notice described in Section 3 or at such other time on the same or on such other date, in any event not later than , 20 , as shall be designated in writing by you.

The Firm Shares and Additional Shares shall be registered in such names and in such denominations as you shall request in writing not later than one full business day prior to the Closing Date or the applicable Option Closing Date, as the case may be. The Firm Shares and Additional Shares shall be delivered to you on the Closing Date or an Option Closing Date, as the case may be, for the respective accounts of the several Underwriters. The Purchase Price payable by the Underwriters shall be reduced by (i) any transfer taxes paid by, or on behalf of, the Underwriters in connection with the transfer of the Shares to the Underwriters duly paid and (ii) any withholding required by law.

6. Conditions to the Underwriters’ Obligations. The obligations of the Sellers to sell the Shares to the Underwriters and the several obligations of the Underwriters to purchase and pay for the Shares on each Applicable Closing Date are subject to the condition that the Registration Statement shall have become effective not later than [ ] (New York City time) on the date hereof.

The several obligations of the Underwriters are subject to the following further conditions:

(a) Subsequent to the execution and delivery of this Agreement and prior to each Applicable Closing Date, there shall not have occurred any change, or any development involving a prospective change, in the condition, financial or otherwise, or in the earnings, business or operations of the Company and its subsidiaries, taken as a whole, from that set forth in the Time of Sale Prospectus that, in your judgment, is material and adverse and that makes it, in your judgment, impracticable to market the Shares on the terms and in the manner contemplated in the Time of Sale Prospectus.

(b) The Underwriters shall have received on each Applicable Closing Date a certificate, dated such Applicable Closing Date and signed on behalf of the Company by an executive officer of the Company, to the effect set forth in Section 6(a) above and to the effect that the representations and warranties of the Company contained in this Agreement are true and correct as of such Applicable Closing Date and that the Company has complied with all of the agreements and satisfied all of the conditions on its part to be performed or satisfied hereunder on or before such Applicable Closing Date.

The officer signing and delivering such certificate may rely upon the best of his or her knowledge as to proceedings threatened.

(c) The Underwriters shall have received on each Applicable Closing Date an opinion of ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ & ▇▇▇▇▇▇, Professional Corporation (“WSGR”), outside counsel for the Company, dated such Applicable Closing Date, substantially in the form attached as Exhibit C hereto.

(d) The Underwriters shall have received on each Applicable Closing Date an opinion of WSGR, counsel for certain Selling Stockholders named therein, dated such Applicable Closing Date, substantially in the form attached as Exhibit C hereto, and for all other Selling Stockholders not named therein, an opinion from such other counsel acceptable to the Underwriters, dated such Applicable Closing Date, an opinion of counsel, including the opinions set forth on Annex I hereto.

(e) The Underwriters shall have received on each Applicable Closing Date an opinion of Pillsbury ▇▇▇▇▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇▇ LLP, counsel for the Underwriters, dated such Applicable Closing Date, in the form and substance agreed upon by such counsel and ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. LLC.

With respect to Section 6(c) and 6(e) above, WSGR and Pillsbury ▇▇▇▇▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇▇ LLP may state that their opinions and beliefs are based upon their participation in the preparation of the Registration Statement, the Time of Sale Prospectus and the Prospectus and any amendments or supplements thereto and review and discussion of the contents thereof, but are without independent check or verification, except as specified. With respect to Section 6(d) above, WSGR may rely upon an opinion or opinions of counsel for any Selling Stockholders and, with respect to factual matters and to the extent such counsel deems appropriate, upon the representations of each Selling Stockholder contained herein and in the Custody Agreement and Power of Attorney of such Selling Stockholder and in other documents and instruments; provided that (A) each such counsel for the Selling Stockholders is satisfactory to your counsel, (B) a copy of each opinion so relied upon is delivered to you and is in form and substance satisfactory to your counsel, (C) copies of such Custody Agreements and Powers of Attorney and of any such other documents and instruments shall be delivered to you and shall be in form and substance satisfactory to your counsel and (D) WSGR shall state in their opinion that they are justified in relying on each such other opinion.

The opinions of WSGR described in Sections 6(c) and 6(d) (and any opinions of counsel for any Selling Stockholder referred to in the immediately preceding paragraph) shall be rendered to the Underwriters at the request of the Company or one or more of the Selling Stockholders, as the case may be, and shall so state therein.

(f) The Underwriters shall have received, on each of the date hereof and each Applicable Closing Date, a letter dated the date hereof or such Applicable Closing Date, as the case may be, in form and substance satisfactory to the Underwriters, from Deloitte & Touche LLP, independent public accountants, containing statements and information of the type ordinarily included in accountants’ “comfort letters” to underwriters with respect to the financial statements and certain financial information contained in the Registration

Statement, the Time of Sale Prospectus and the Prospectus; provided that the letter delivered on each Applicable Closing Date shall use a “cut-off date” not earlier than three days prior to such Applicable Closing Date.

(g) The “lock-up” agreements, each substantially in the form of Exhibit A hereto, between you and certain stockholders, officers and directors of the Company relating to sales and certain other dispositions of shares of Common Stock or certain other securities, delivered to you on or before the date hereof, shall be in full force and effect on each Applicable Closing Date.

(h) The several obligations of the Underwriters to purchase Additional Shares hereunder are subject to the delivery to you on the applicable Option Closing Date of such documents as you may reasonably request with respect to the good standing of the Company, the due authorization and issuance of the Additional Shares to be sold on such Option Closing Date and other matters related to the issuance of such Additional Shares.

(i) The chief financial officer of the Company shall have delivered to the Underwriters on each of the date hereof and the Closing Date a certificate in a form reasonably acceptable to ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. LLC.

7. Covenants of the Company. The Company covenants with each Underwriter as follows:

(a) To furnish to you, without charge, four signed copies of the Registration Statement (including exhibits thereto) and for delivery to each other Underwriter a conformed copy of the Registration Statement (without exhibits thereto) and to furnish to you in New York City, without charge, prior to 10:00 a.m. New York City time on the business day next succeeding the date of this Agreement and during the period mentioned in Section 7(e) or 7(f) below, as many copies of the Time of Sale Prospectus, the Prospectus and any supplements and amendments thereto or to the Registration Statement as you may reasonably request.

(b) Before amending or supplementing the Registration Statement, the Time of Sale Prospectus or the Prospectus, to furnish to you a copy of each such proposed amendment or supplement and not to file any such proposed amendment or supplement to which you reasonably object, and to file with the Commission within the applicable period specified in Rule 424(b) under the Securities Act any prospectus required to be filed pursuant to such Rule.

(c) To furnish to you a copy of each proposed free writing prospectus to be prepared by or on behalf of, used by, or referred to by the Company and not to use or refer to any proposed free writing prospectus to which you reasonably object.

(d) Not to take any action that would result in an Underwriter or the Company being required to file with the Commission pursuant to Rule 433(d)

under the Securities Act a free writing prospectus prepared by or on behalf of the Underwriter that the Underwriter otherwise would not have been required to file thereunder.

(e) If the Time of Sale Prospectus is being used to solicit offers to buy the Shares at a time when the Prospectus is not yet available to prospective purchasers and any event shall occur or condition exist as a result of which it is necessary to amend or supplement the Time of Sale Prospectus in order to make the statements therein, in the light of the circumstances, not misleading, or if any event shall occur or condition exist as a result of which the Time of Sale Prospectus conflicts with the information contained in the Registration Statement then on file, or if, in the opinion of counsel for the Underwriters, it is necessary to amend or supplement the Time of Sale Prospectus to comply with applicable law, forthwith to prepare, file with the Commission and furnish, at its own expense, to the Underwriters and to any dealer upon request, either amendments or supplements to the Time of Sale Prospectus so that the statements in the Time of Sale Prospectus as so amended or supplemented will not, in the light of the circumstances when the Time of Sale Prospectus is delivered to a prospective purchaser, be misleading or so that the Time of Sale Prospectus, as amended or supplemented, will no longer conflict with the Registration Statement, or so that the Time of Sale Prospectus, as amended or supplemented, will comply with applicable law.

(f) If, during such period after the first date of the public offering of the Shares as in the opinion of counsel for the Underwriters the Prospectus (or in lieu thereof the notice referred to in Rule 173(a) of the Securities Act) is required by law to be delivered in connection with sales by an Underwriter or dealer, any event shall occur or condition exist as a result of which it is necessary to amend or supplement the Prospectus in order to make the statements therein, in the light of the circumstances when the Prospectus (or in lieu thereof the notice referred to in Rule 173(a) of the Securities Act) is delivered to a purchaser, not misleading, or if, in the opinion of counsel for the Underwriters, it is necessary to amend or supplement the Prospectus to comply with applicable law, forthwith to prepare, file with the Commission and furnish, at its own expense, to the Underwriters and to the dealers (whose names and addresses you will furnish to the Company) to which Shares may have been sold by you on behalf of the Underwriters and to any other dealers upon request, either amendments or supplements to the Prospectus so that the statements in the Prospectus as so amended or supplemented will not, in the light of the circumstances when the Prospectus (or in lieu thereof the notice referred to in Rule 173(a) of the Securities Act) is delivered to a purchaser, be misleading or so that the Prospectus, as amended or supplemented, will comply with applicable law.

(g) To endeavor to qualify the Shares for offer and sale under the securities or Blue Sky laws of such jurisdictions as you shall reasonably request; provided that the Company shall not be required to (i) qualify as a foreign corporation or other entity or as a dealer in securities in any such jurisdiction or (ii) subject itself to taxation in any such jurisdiction if it is not otherwise so subject.

(h) To make generally available to the Company’s security holders and to you as soon as practicable an earnings statement covering a period of at least twelve months beginning with the first fiscal quarter of the Company occurring after the date of this Agreement which shall satisfy the provisions of Section 11(a) of the Securities Act and the rules and regulations of the Commission thereunder.

(i) If any Seller is not a U.S. person for U.S. federal income tax purposes, the Company will deliver to each Underwriter (or its agent), on or before the Closing Date, (i) a certificate with respect to the Company’s status as a “United States real property holding corporation,” dated not more than thirty (30) days prior to the Closing Date, as described in Treasury Regulations Sections 1.897-2(h) and 1.1445-2(c)(3), and (ii) proof of delivery to the IRS of the required notice, as described in Treasury Regulations Section 1.897-2(h)(2).

(j) The Company will promptly notify ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. LLC if the Company ceases to be an Emerging Growth Company at any time prior to the later of (a) completion of the distribution of the Shares within the meaning of the Securities Act and (b) completion of the Restricted Period referred to in Section 3.

(k) If at any time following the distribution of any Written Testing-the-Waters Communication there occurred or occurs an event or development as a result of which such Written Testing-the-Waters Communication included or would include an untrue statement of a material fact or omitted or would omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances existing at that subsequent time, not misleading, the Company will promptly notify ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. LLC and will promptly amend or supplement, at its own expense, such Written Testing-the-Waters Communication to eliminate or correct such untrue statement or omission.

8. Covenants of the Sellers. Each Seller, severally and not jointly, covenants with each Underwriter as follows:

(a) Each Seller will deliver to each Underwriter (or its agent), prior to or at the Closing Date, a properly completed and executed Internal Revenue Service (“IRS”) Form W-9 or an IRS Form W-8, as appropriate, together with all required attachments to such form.

9. Expenses. Whether or not the transactions contemplated in this Agreement are consummated or this Agreement is terminated, the Sellers agree to pay or cause to be paid all expenses incident to the performance of their obligations under this Agreement, including: (i) the fees, disbursements and expenses of the Company’s counsel, the Company’s accountants and counsel for the Selling Stockholders (unless such Selling Stockholder has retained and paid for its own counsel) in connection with

the registration and delivery of the Shares under the Securities Act and all other fees or expenses in connection with the preparation and filing of the Registration Statement, any preliminary prospectus, the Time of Sale Prospectus, the Prospectus, any free writing prospectus prepared by or on behalf of, used by, or referred to by the Company and amendments and supplements to any of the foregoing, including all printing costs associated therewith, and the mailing and delivering of copies thereof to the Underwriters and dealers, in the quantities hereinabove specified, (ii) all costs and expenses related to the transfer and delivery of the Shares to the Underwriters, including any transfer or other taxes payable thereon, (iii) the reasonable, documented cost of printing or producing any Blue Sky or Legal Investment memorandum in connection with the offer and sale of the Shares under state securities laws and all expenses in connection with the qualification of the Shares for offer and sale under state securities laws as provided in Section 7(g) hereof, including filing fees and the reasonable, documented fees and disbursements of counsel for the Underwriters in connection with such qualification and in connection with the Blue Sky or Legal Investment memorandum, (iv) all filing fees and the reasonable, documented fees and disbursements of counsel to the Underwriters incurred in connection with the review and qualification of the offering of the Shares by FINRA (provided that the amount payable by the Company with respect to fees and disbursements of counsel for the Underwriters incurred pursuant to subsections (iii) and (iv) shall not exceed $30,000), (v) all fees and expenses in connection with the preparation and filing of the registration statement on Form 8-A relating to the Common Stock and all costs and expenses incident to listing the Shares on [the NYSE/NYSE MKT/The NASDAQ Global Market] and other national securities exchanges and foreign stock exchanges, (vi) the cost of printing certificates representing the Shares, (vii) the costs and charges of any transfer agent, registrar or depositary, (viii) the costs and expenses of the Company relating to investor presentations on any “road show” undertaken in connection with the marketing of the offering of the Shares, including, without limitation, expenses associated with the preparation or dissemination of any electronic road show, expenses associated with the production of road show slides and graphics, fees and expenses of any consultants engaged in connection with the road show presentations with the prior approval of the Company, travel and lodging expenses of the representatives and officers of the Company and any such consultants, and 50% of the cost of any aircraft chartered in connection with the road show (with the other 50% of such aircraft costs to be borne by the Underwriters), (ix) the document production charges and expenses associated with printing this Agreement, and (x) all other costs and expenses incident to the performance of the obligations of the Company hereunder for which provision is not otherwise made in this Section. It is understood, however, that except as provided in this Section, Section 11 entitled “Indemnity and Contribution”, the last paragraph of Section 13 below, the Underwriters will pay all of their costs and expenses, including fees and disbursements of their counsel, stock transfer taxes payable on resale of any of the Shares by them and any advertising expenses connected with any offers they may make and travel and lodging expenses incurred by them in connection with any road show.

The provisions of this Section shall not supersede or otherwise affect any agreement that the Sellers may otherwise have for the allocation of such expenses among themselves.

10. Covenants of the Underwriters. Each Underwriter severally covenants with the Company not to take any action that would result in the Company being required to file with the Commission under Rule 433(d) a free writing prospectus prepared by or on behalf of such Underwriter that otherwise would not be required to be filed by the Company thereunder, but for the action of the Underwriter.

11. Indemnity and Contribution. (a) The Company agrees to indemnify and hold harmless each Underwriter, each person, if any, who controls any Underwriter within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act, and each affiliate of any Underwriter within the meaning of Rule 405 under the Securities Act from and against any and all losses, claims, damages and liabilities (including, without limitation, any legal or other expenses reasonably incurred in connection with defending or investigating any such action or claim) caused by any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement or any amendment thereof, any preliminary prospectus, the Time of Sale Prospectus or any amendment or supplement thereto, any issuer free writing prospectus as defined in Rule 433(h) under the Securities Act, any Company information that the Company has filed, or is required to file, pursuant to Rule 433(d) under the Securities Act, any “road show” as defined in Rule 433(h) under the Securities Act (a “road show”), or the Prospectus or any amendment or supplement thereto, or any Written Testing-the-Waters Communication or caused by any omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, except insofar as such losses, claims, damages or liabilities are caused by any such untrue statement or omission or alleged untrue statement or omission based upon information relating to any Underwriter furnished to the Company in writing by such Underwriter through you expressly for use therein.

(b) Each Selling Stockholder agrees, severally and not jointly, to indemnify and hold harmless (i) each Underwriter, each person, if any, who controls any Underwriter within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act, and each affiliate of any Underwriter within the meaning of Rule 405 under the Securities Act, and (ii) the Company, its directors, its officers who sign the Registration Statement and each person, if any, who controls the Company within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act, from and against any and all losses, claims, damages and liabilities (including, without limitation, any legal or other expenses reasonably incurred in connection with defending or investigating any such action or claim) caused by any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement or any amendment thereof, any preliminary prospectus, the Time of Sale Prospectus or any amendment or supplement thereto, any issuer free writing prospectus as defined in Rule 433(h) under the Securities Act, any Company information that the Company has filed, or is required to file, pursuant to Rule 433(d) under the Securities Act, any road show, or the Prospectus or any amendment or supplement thereto, or any Written Testing-the-Waters Communication or caused by any omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, (i) except

insofar as such losses, claims, damages or liabilities are caused by any such untrue statement or omission or alleged untrue statement or omission based upon information relating to any Underwriter furnished to the Company in writing by such Underwriter through you expressly for use therein and (ii) only to the extent such losses, claims, damages or liabilities are caused by any untrue statement or omission or alleged untrue statement or omission made in reliance on and in conformity with the Selling Stockholder Information provided by and relating to such Selling Stockholder.

(c) Each Underwriter agrees, severally and not jointly, to indemnify and hold harmless the Company, the Selling Stockholders, the directors of the Company, the officers of the Company who sign the Registration Statement and each person, if any, who controls the Company or any Selling Stockholder within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act from and against any and all losses, claims, damages and liabilities (including, without limitation, any legal or other expenses reasonably incurred in connection with defending or investigating any such action or claim) caused by any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement or any amendment thereof, any preliminary prospectus, the Time of Sale Prospectus or any amendment or supplement thereto, any issuer free writing prospectus as defined in Rule 433(h) under the Securities Act, any Company information that the Company has filed, or is required to file, pursuant to Rule 433(d) under the Securities Act, or the Prospectus or any amendment or supplement thereto, or caused by any omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, but only with reference to information relating to such Underwriter furnished to the Company in writing by such Underwriter through you expressly for use in the Registration Statement, any preliminary prospectus, the Time of Sale Prospectus, any issuer free writing prospectus, or the Prospectus or any amendment or supplement thereto.

(d) In case any proceeding (including any governmental investigation) shall be instituted involving any person in respect of which indemnity may be sought pursuant to Section 11(a), Section 11(b) or Section 11(c), such person (the “indemnified party”) shall promptly notify the person against whom such indemnity may be sought (the “indemnifying party”) in writing and the indemnifying party, upon request of the indemnified party, shall retain counsel reasonably satisfactory to the indemnified party to represent the indemnified party and any others the indemnifying party may designate in such proceeding and shall pay the reasonably incurred and documented fees and disbursements of such counsel related to such proceeding. In any such proceeding, any indemnified party shall have the right to retain its own counsel, but the fees and expenses of such counsel shall be at the expense of such indemnified party unless (i) the indemnifying party and the indemnified party shall have mutually agreed in writing to the retention of such counsel or (ii) the named parties to any such proceeding (including any impleaded parties) include both the indemnifying party and the indemnified party and representation of both parties by the same counsel

would be inappropriate due to actual or potential differing interests between them. It is understood that the indemnifying party shall not, in respect of the legal expenses of any indemnified party in connection with any proceeding or related proceedings in the same jurisdiction, be liable for (i) the fees and expenses of more than one separate firm (in addition to any local counsel) for all Underwriters and all persons, if any, who control any Underwriter within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act or who are affiliates of any Underwriter within the meaning of Rule 405 under the Securities Act, (ii) the fees and expenses of more than one separate firm (in addition to any local counsel) for the Company, its directors, its officers who sign the Registration Statement and each person, if any, who controls the Company within the meaning of either such Section and (iii) the fees and expenses of more than one separate firm (in addition to any local counsel) for all Selling Stockholders and all persons, if any, who control any Selling Stockholder within the meaning of either such Section, and that all such fees and expenses shall be reimbursed as they are incurred. In the case of any such separate firm for the Underwriters and such control persons and affiliates of any Underwriters, such firm shall be designated in writing by ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. LLC. In the case of any such separate firm for the Company, and such directors, officers and control persons of the Company, such firm shall be designated in writing by the Company. In the case of any such separate firm for the Selling Stockholders and such control persons of any Selling Stockholders, such firm shall be designated in writing by the persons named as attorneys-in-fact for the Selling Stockholders under the Powers of Attorney. The indemnifying party shall not be liable for any settlement of any proceeding effected without its written consent, but if settled with such consent or if there be a final judgment for the plaintiff, the indemnifying party agrees to indemnify the indemnified party from and against any loss or liability by reason of such settlement or judgment. Notwithstanding the foregoing sentence, if at any time an indemnified party shall have requested an indemnifying party to reimburse the indemnified party for fees and expenses of counsel as contemplated by the second and third sentences of this paragraph, the indemnifying party agrees that it shall be liable for any settlement of any proceeding effected without its written consent if (i) such settlement is entered into more than 45 days after receipt by such indemnifying party of the aforesaid request and (ii) such indemnifying party shall not have reimbursed the indemnified party in accordance with such request prior to the date of such settlement. No indemnifying party shall, without the prior written consent of the indemnified party, effect any settlement of any pending or threatened proceeding in respect of which any indemnified party is or could have been a party and indemnity could have been sought hereunder by such indemnified party, unless such settlement (x) includes an unconditional release of such indemnified party from all liability on claims that are the subject matter of such proceeding and (y) does not contain any statement as to or any admission of fault, culpability or failure to act by or on behalf of any indemnified party.

(e) To the extent the indemnification provided for in Section 11(a), Section 11(b) or Section 11(c) is unavailable to an indemnified party or

insufficient in respect of any losses, claims, damages or liabilities referred to therein, then each indemnifying party under such paragraph, in lieu of indemnifying such indemnified party thereunder, shall contribute to the amount paid or payable by such indemnified party as a result of such losses, claims, damages or liabilities (i) in such proportion as is appropriate to reflect the relative benefits received by the indemnifying party or parties on the one hand and the indemnified party or parties on the other hand from the offering of the Shares or (ii) if the allocation provided by clause 11(e)(i) above is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause 11(e)(i) above but also the relative fault of the indemnifying party or parties on the one hand and of the indemnified party or parties on the other hand in connection with the statements or omissions that resulted in such losses, claims, damages or liabilities, as well as any other relevant equitable considerations. The relative benefits received by the Sellers on the one hand and the Underwriters on the other hand in connection with the offering of the Shares shall be deemed to be in the same respective proportions as the net proceeds from the offering of the Shares (before deducting expenses) received by each Seller and the total underwriting discounts and commissions received by the Underwriters, in each case as set forth in the table on the cover of the Prospectus, bear to the aggregate Public Offering Price of the Shares. The relative fault of the Sellers on the one hand and the Underwriters on the other hand shall be determined by reference to, among other things, whether the untrue or alleged untrue statement of a material fact or the omission or alleged omission to state a material fact relates to information supplied by the Sellers or by the Underwriters and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission. The Underwriters’ respective obligations to contribute pursuant to this Section 11 are several in proportion to the respective number of Shares they have purchased hereunder, and not joint.

(f) The Sellers and the Underwriters agree that it would not be just or equitable if contribution pursuant to this Section 11 were determined by pro rata allocation (even if the Underwriters were treated as one entity for such purpose) or by any other method of allocation that does not take account of the equitable considerations referred to in Section 11(e). The amount paid or payable by an indemnified party as a result of the losses, claims, damages and liabilities referred to in Section 11(e) shall be deemed to include, subject to the limitations set forth above, any legal or other expenses reasonably incurred by such indemnified party in connection with investigating or defending any such action or claim. Notwithstanding the provisions of this Section 11, no Underwriter shall be required to contribute any amount in excess of the amount by which the total price at which the Shares underwritten by it and distributed to the public were offered to the public exceeds the amount of any damages that such Underwriter has otherwise been required to pay by reason of such untrue or alleged untrue statement or omission or alleged omission. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The remedies provided for in this Section 11 are not exclusive and shall not limit any rights or remedies which may otherwise be available to any indemnified party at law or in equity.

(g) The indemnity and contribution provisions contained in this Section 11 and the representations, warranties and other statements of the Company and the Selling Stockholders contained in this Agreement shall remain operative and in full force and effect regardless of (i) any termination of this Agreement, (ii) any investigation made by or on behalf of any Underwriter, any person controlling any Underwriter or any affiliate of any Underwriter, any Selling Stockholder or any person controlling any Selling Stockholder, or the Company, its officers or directors or any person controlling the Company and (iii) acceptance of and payment for any of the Shares.

(h) Notwithstanding anything to the contrary in this Agreement, the liability of each Selling Stockholder under the indemnity and contribution agreements contain in this Section 11, shall be limited in the aggregate to an amount equal to the aggregate Public Offering Price of the Shares sold by such Selling Stockholder (after deducting underwriting discounts and commissions but before expenses) under this Agreement.

12. Termination. The Underwriters may terminate this Agreement by notice given by you to the Company, if after the execution and delivery of this Agreement and prior to the Closing Date (i) trading generally shall have been suspended or materially limited on, or by, as the case may be, any of the New York Stock Exchange or The NASDAQ Global Market, (ii) trading of any securities of the Company shall have been suspended on any exchange or in any over-the-counter market, (iii) a material disruption in securities settlement, payment or clearance services in the United States shall have occurred, (iv) any moratorium on commercial banking activities shall have been declared by Federal or New York State authorities or (v) there shall have occurred any outbreak or escalation of hostilities, or any change in financial markets, or any calamity or crisis that, in your judgment, is material and adverse and which, singly or together with any other event specified in this clause (v), makes it, in your judgment, impracticable or inadvisable to proceed with the offer, sale or delivery of the Shares on the terms and in the manner contemplated in the Time of Sale Prospectus or the Prospectus.

13. Effectiveness; Defaulting Underwriters. This Agreement shall become effective upon the execution and delivery hereof by the parties hereto.

If, on the Closing Date or an Option Closing Date, as the case may be, any one or more of the Underwriters shall fail or refuse to purchase Shares that it has or they have agreed to purchase hereunder on such date, and the aggregate number of Shares which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase is not more than one-tenth of the aggregate number of the Shares to be purchased on such date, the other Underwriters shall be obligated severally in the proportions that the number of Firm Shares set forth opposite their respective names in Schedule II bears to the aggregate number of Firm Shares set forth opposite the names of all such non-defaulting Underwriters, or in such other proportions as you may specify, to

purchase the Shares which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase on such date; provided that in no event shall the number of Shares that any Underwriter has agreed to purchase pursuant to this Agreement be increased pursuant to this Section 13 by an amount in excess of one-ninth of such number of Shares without the written consent of such Underwriter. If, on the Closing Date, any Underwriter or Underwriters shall fail or refuse to purchase Firm Shares and the aggregate number of Firm Shares with respect to which such default occurs is more than one-tenth of the aggregate number of Firm Shares to be purchased on such date, and arrangements satisfactory to you, the Company and the Selling Stockholders for the purchase of such Firm Shares are not made within 36 hours after such default, this Agreement shall terminate without liability on the part of any non-defaulting Underwriter, the Company or the Selling Stockholders. In any such case either you or the relevant Sellers shall have the right to postpone the Closing Date, but in no event for longer than seven days, in order that the required changes, if any, in the Registration Statement, in the Time of Sale Prospectus, in the Prospectus or in any other documents or arrangements may be effected. If, on an Option Closing Date, any Underwriter or Underwriters shall fail or refuse to purchase Additional Shares and the aggregate number of Additional Shares with respect to which such default occurs is more than one-tenth of the aggregate number of Additional Shares to be purchased on such Option Closing Date, the non-defaulting Underwriters shall have the option to (i) terminate their obligation hereunder to purchase the Additional Shares to be sold on such Option Closing Date or (ii) purchase not less than the number of Additional Shares that such non-defaulting Underwriters would have been obligated to purchase in the absence of such default. Any action taken under this paragraph shall not relieve any defaulting Underwriter from liability in respect of any default of such Underwriter under this Agreement.

If this Agreement shall be terminated by the Underwriters, or any of them, because of any failure or refusal on the part of any Seller to comply with the terms or to fulfill any of the conditions of this Agreement, or if for any reason any Seller shall be unable to perform its obligations under this Agreement, the Sellers will reimburse the Underwriters or such Underwriters as have so terminated this Agreement with respect to themselves, severally, for all out-of-pocket expenses (including the fees and disbursements of their counsel) reasonably incurred by such Underwriters in connection with this Agreement or the offering contemplated hereunder.

14. Entire Agreement. (a) This Agreement, together with any contemporaneous written agreements and any prior written agreements (to the extent not superseded by this Agreement) that relate to the offering of the Shares, represents the entire agreement between the Company and the Selling Stockholders, on the one hand, and the Underwriters, on the other, with respect to the preparation of any preliminary prospectus, the Time of Sale Prospectus, the Prospectus, the conduct of the offering, and the purchase and sale of the Shares.

(b) The Company acknowledges that in connection with the offering of the Shares: (i) the Underwriters have acted at arms-length, are not agents of, and owe no fiduciary duties to, the Company or any other person, (ii) the Underwriters owe the Company only those duties and obligations set forth in this

Agreement and prior written agreements (to the extent not superseded by this Agreement), if any, and (iii) the Underwriters may have interests that differ from those of the Company. The Company waives to the full extent permitted by applicable law any claims it may have against the Underwriters arising from an alleged breach of fiduciary duty in connection with the offering of the Shares.

15. Counterparts. This Agreement may be signed in two or more counterparts, each of which shall be an original, with the same effect as if the signatures thereto and hereto were upon the same instrument.

16. Applicable Law. This Agreement shall be governed by and construed in accordance with the internal laws of the State of New York.

17. Headings. The headings of the sections of this Agreement have been inserted for convenience of reference only and shall not be deemed a part of this Agreement.

18. Notices. All communications hereunder shall be in writing and effective only upon receipt and if to the Underwriters shall be delivered, mailed or sent to you at ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. LLC, ▇▇▇▇ ▇▇▇▇▇▇▇▇, ▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇, Attention: Equity Syndicate Desk, with a copy to the Legal Department; if to the Company shall be delivered, mailed or sent to ▇ ▇▇▇▇ ▇▇▇▇▇▇▇▇ ▇▇▇▇▇, ▇▇▇ ▇▇▇▇, ▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇ and if to the Selling Stockholders shall be delivered, mailed or sent to [address].


Very truly yours,

A10 Networks, Inc.

By:
		Name:
		Title:


The Selling Stockholders named in Schedule I hereto, acting severally

By:
		Attorney-in Fact

Accepted as of the date hereof

▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. LLC

▇▇▇▇▇▇▇ Lynch, Pierce, ▇▇▇▇▇▇ & ▇▇▇▇▇

Incorporated

▇.▇. ▇▇▇▇▇▇ Securities LLC

RBC Capital Markets, LLC

Acting severally on behalf of themselves and the

several Underwriters named in Schedule II hereto


By:		▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. LLC

By:
		Name:
		Title:

By:		▇▇▇▇▇▇▇ Lynch, Pierce, ▇▇▇▇▇▇ & ▇▇▇▇▇ Incorporated

By:
		Name:
		Title:

By:		▇.▇. ▇▇▇▇▇▇ Securities LLC

By:
		Name:
		Title:


By:		RBC Capital Markets, LLC

By:
		Name:
		Title:

SCHEDULE I


Selling Stockholder		Number of Firm Shares To Be Sold

[NAMES OF SELLING STOCKHOLDERS]









Total:

I-1

SCHEDULE II


Underwriter		Number of Firm Shares To Be Purchased

▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. LLC

▇▇▇▇▇▇▇ ▇▇▇▇▇, ▇▇▇▇▇▇ ▇▇▇▇▇▇ & ▇▇▇▇▇ Incorporated

▇.▇. ▇▇▇▇▇▇ Securities LLC

RBC Capital Markets, LLC

Pacific Crest Securities LLC

▇▇▇▇▇▇▇▇▇▇▇ & Co. Inc.

Total:

II-1

SCHEDULE III

Time of Sale Prospectus

Preliminary Prospectus issued [date]

[all free writing prospectuses filed by the Company under Rule 433(d) of the Securities Act]

[free writing prospectus containing a description of terms that does not reflect final terms, if the Time of Sale Prospectus does not include a final term sheet]

[orally communicated pricing information such as price per share and size of offering if a Rule 134 pricing term sheet is used at the time of sale instead of a pricing term sheet filed by the Company under Rule 433(d) as a free writing prospectus]

III-1

SCHEDULE IV

III-2

EXHIBIT A

[FORM OF LOCK-UP LETTER]

, 20

▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. LLC

▇▇▇▇▇▇▇ Lynch, Pierce, ▇▇▇▇▇▇ & ▇▇▇▇▇

Incorporated

▇.▇. ▇▇▇▇▇▇ Securities LLC

RBC Capital Markets, LLC

c/o Morgan ▇▇▇▇▇▇▇ & Co. LLC

▇▇▇▇ ▇▇▇▇▇▇▇▇

▇▇▇ ▇▇▇▇, ▇▇ ▇▇▇▇▇

Ladies and Gentlemen:

The undersigned understands that ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. LLC (“▇▇▇▇▇▇ ▇▇▇▇▇▇▇”), ▇▇▇▇▇▇▇ ▇▇▇▇▇, ▇▇▇▇▇▇ ▇▇▇▇▇▇ & ▇▇▇▇▇ Incorporated (“Merrill”), ▇.▇. ▇▇▇▇▇▇ Securities LLC (“▇.▇. ▇▇▇▇▇▇”) and RBC Capital Markets, LLC (“RBC Capital”) propose to enter into an Underwriting Agreement (the “Underwriting Agreement”) with A10 Networks, Inc., a California corporation together with any successor entities (the “Company”), and certain selling stockholders of the Company named in the Underwriting Agreement, if any, providing for the public offering (the “Public Offering”) by the several Underwriters, including ▇▇▇▇▇▇ Stanley, Merrill, ▇.▇. ▇▇▇▇▇▇ and RBC Capital (the “Underwriters”), of shares (the “Shares”) of the common stock of the Company (the “Common Stock”).

To induce the Underwriters that may participate in the Public Offering to continue their efforts in connection with the Public Offering, the undersigned hereby agrees that, without the prior written consent of ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ on behalf of the Underwriters, it will not, during the period commencing on the date hereof and ending 180 days after the date of the final prospectus (the “Restricted Period)” relating to the Public Offering (the “Prospectus”), (1) offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, lend, or otherwise transfer or dispose of, directly or indirectly, any shares of Common Stock beneficially owned (as such term is used in Rule 13d-3 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”)), by the undersigned or any other securities so owned convertible into or exercisable or exchangeable for Common Stock or (2) enter into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of the Common Stock, whether any such transaction described in clause (1) or (2) above is to be settled by delivery of Common Stock or such other securities, in cash or otherwise. The foregoing sentence shall not apply to:

(a) transactions relating to shares of Common Stock or other securities acquired in open market transactions after the completion of the Public Offering, provided that no filing under Section 16(a) of the Exchange Act shall be required or shall be voluntarily made in connection with subsequent sales of Common Stock or other securities acquired in such open market transactions;

A-1

(b) the transfer of shares of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock (i) to the spouse, domestic partner, parent, sibling, child or grandchild of the undersigned or any other person with whom the undersigned has a relationship by blood, marriage or adoption not more remote than first cousin (each, an “immediate family member”) or to a trust, or other entity formed for estate planning purposes, formed for the benefit of the undersigned or of an immediate family member of the undersigned , (ii) by bona fide gift, will or intestacy, (iii) if the undersigned is a corporation, partnership, limited liability company or other business entity (A) to another corporation, partnership, limited liability company or other business entity that controls, is controlled by or is under common control with the undersigned or (B) as part of a disposition, transfer or distribution by the undersigned to its equity holders or (iv) if the undersigned is a trust, to a trustor or beneficiary of the trust; provided that in the case of any transfer or distribution pursuant to this clause (b), (i) each transferee, donee or distributee shall sign and deliver a lock-up agreement substantially in the form of this agreement prior to or upon such transfer or distribution, and (ii) no filing under Section 16(a) of the Exchange Act, reporting a reduction of beneficial ownership of Shares of Common Stock, shall be required or shall be voluntarily made during the Restricted Period in connection with such transfer or distribution;

(c) the receipt by the undersigned from the Company of shares of Common Stock upon the vesting of restricted stock awards issued pursuant to the Company’s equity incentive plans or the transfer of shares of Common Stock or any securities convertible into Common Stock to the Company upon a vesting event of the Company’s securities or upon the exercise of options or warrants to purchase the Company’s securities, in each case on a “cashless” or “net exercise” basis or to cover tax withholding obligations of the undersigned in connection with such vesting or exercise, provided that no filing under Section 16(a) of the Exchange Act shall be required or shall be voluntarily made during the Restricted Period;

(d) the disposition of shares of Common Stock to the Company solely in connection with the payment of taxes due with respect to the vesting of restricted stock awards issued pursuant to the Company’s equity incentive plans, which plans are in each case described in the Registration Statement, provided that no filing under Section 16(a) of the Exchange Act shall be required or shall be voluntarily made during the Restricted Period in connection with such disposition;

(e) the transfer of shares of Common Stock or any security convertible into or exercisable or exchangeable for Common Stock to the Company, pursuant to agreements under which the Company has the option to repurchase such shares or securities or a right of first refusal with respect to transfers of such shares or securities, provided that no filing

A-2

under Section 16(a) of the Exchange Act, reporting a reduction of beneficial ownership of Shares of Common Stock, shall be required or shall be voluntarily made during the Restricted Period;

(f) the establishment of a trading plan pursuant to Rule 10b5-1 under the Exchange Act for the transfer of shares of Common Stock, provided that such plan does not provide for the transfer of Common Stock during the Restricted Period and no public announcement or filing under the Exchange Act regarding the establishment of such plan shall be required of or voluntarily made by or on behalf of the undersigned or the Company;

(g) the conversion of the outstanding preferred stock of the Company into shares of Common Stock of the Company, provided that such shares of Common Stock remain subject to the terms of this letter;

(h) if the undersigned is an individual, the transfer of shares of Common Stock or any security convertible into or exercisable or exchangeable for Common Stock that occurs by operation of law, such as pursuant to a qualified domestic order or in connection with a divorce settlement, provided that the undersigned shall use its reasonable best efforts to cause the transferee to sign and deliver a lock-up agreement substantially in the form of this agreement prior to such transfer, and provided further, that any filing under Section 16(a) of the Exchange Act that is required to be made during the Restricted Period as a result of such transfer, states that such transfer has occurred by operation of law; or

(i) the sale and transfer of shares of Common Stock by the undersigned to the Underwriters in the Public Offering pursuant to the terms of the Underwriting Agreement.

In addition, the undersigned agrees that, without the prior written consent of ▇▇▇▇▇▇ ▇▇▇▇▇▇▇, on behalf of the Underwriters, it will not, during the Restricted Period, make any demand for or exercise any right with respect to, the registration of any shares of Common Stock or any security convertible into or exercisable or exchangeable for Common Stock. The undersigned also agrees and consents to the entry of stop transfer instructions with the Company’s transfer agent and registrar against the transfer of the undersigned’s shares of Common Stock except in compliance with the foregoing restrictions.

If the undersigned is an officer or director of the Company, the undersigned further agrees that the foregoing provisions shall be equally applicable to any issuer-directed Shares the undersigned may purchase in the offering.

If the undersigned is an officer or director of the Company, (i) ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ agrees that, at least three business days before the effective date of any release or waiver of the foregoing restrictions in connection with a transfer of shares of Common Stock, ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ will notify the Company of the impending release or waiver, and (ii) the Company has agreed in the Underwriting Agreement to announce the impending release

A-3

or waiver by press release through a major news service at least two business days before the effective date of the release or waiver. Any release or waiver granted by ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ hereunder to any such officer or director shall only be effective two business days after the publication date of such press release. The provisions of this paragraph will not apply if (a) the release or waiver is effected solely to permit a transfer not for consideration and (b) the transferee has agreed in writing to be bound by the same terms described in this letter to the extent and for the duration that such terms remain in effect at the time of the transfer.

The undersigned understands that the Company and the Underwriters are relying upon this agreement in proceeding toward consummation of the Public Offering. The undersigned further understands that this agreement is irrevocable and shall be binding upon the undersigned’s heirs, legal representatives, successors and assigns.

Whether or not the Public Offering actually occurs depends on a number of factors, including market conditions. Any Public Offering will only be made pursuant to an Underwriting Agreement, the terms of which are subject to negotiation between the Company and the Underwriters.

This agreement shall automatically terminate upon the earlier to occur of: (i) the date the Company provides the Underwriters with written notice that it does not intend to proceed with the Public Offering, but only in the event such notice is given prior to the execution of the Underwriting Agreement; (ii) the termination of the Underwriting Agreement before the sale of any Common Stock to the Underwriters, or (iii) September 30, 2014, if the Underwriting Agreement has not been executed by that date.

Very truly yours,

(Name)

(Address)

A-4

EXHIBIT B

FORM OF WAIVER OF LOCK-UP

, 20

[Name and Address of

Officer or Director

Requesting Waiver]

Dear Mr./Ms. [Name]:

This letter is being delivered to you in connection with the offering by A10 Networks, Inc. (the “Company”) of shares of common stock, $ par value (the “Common Stock”), of the Company and the lock-up letter dated , 20 (the “Lock-up Letter”), executed by you in connection with such offering, and your request for a [waiver] [release] dated , 20 , with respect to shares of Common Stock (the “Shares”).

▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. LLC hereby agrees to [waive] [release] the transfer restrictions set forth in the Lock-up Letter, but only with respect to the Shares, effective , 20 ; provided, however, that such [waiver] [release] is conditioned on the Company announcing the impending [waiver] [release] by press release through a major news service at least two business days before effectiveness of such [waiver] [release]. This letter will serve as notice to the Company of the impending [waiver] [release].

Except as expressly [waived] [released] hereby, the Lock-up Letter shall remain in full force and effect.

Very truly yours,

▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. LLC

B-1


Acting severally on behalf of themselves and the several Underwriters named in Schedule I hereto

By:
		Name:
		Title:

cc: Company

B-2

FORM OF PRESS RELEASE

A10 Networks, Inc.

[Date]

A10 Networks, Inc. (the “Company”) announced today that ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. LLC, the lead book-running manager in the Company’s recent public sale of shares of common stock is [waiving][releasing] a lock-up restriction with respect to shares of the Company’s common stock held by [certain officers or directors] [an officer or director] of the Company. The [waiver][release] will take effect on , 20 , and the shares may be sold on or after such date.

This press release is not an offer for sale of the securities in the United States or in any other jurisdiction where such offer is prohibited, and such securities may not be offered or sold in the United States absent registration or an exemption from registration under the United States Securities Act of 1933, as amended.

B-3

ANNEX I

I-1

Shares A10 NETWORKS, INC. COMMON STOCK $ PAR VALUE PER SHARE UNDERWRITING AGREEMENT

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