SCHEDULE 14A INFORMATION

Proxy Statement Pursuant to Section 14(a) of the Securities

Exchange Act of 1934

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☐	Preliminary Proxy Statement
☐	Confidential, For Use of the Commission Only (as permitted by Rule 14a-6(e)(2))
☐	Definitive Proxy Statement
☒	Definitive Additional Materials
☐	Soliciting Material Pursuant to § 240.14a-12

NETSCOUT SYSTEMS, INC.

(Name of Registrant as Specified in Its Charter)

(Name of Person(s) Filing Proxy Statement, if Other Than the Registrant)

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		Vote by Internet
		• Go to www.investorvote.com/NTCT
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Important Notice Regarding the Availability of Proxy Materials for the

NetScout Systems, Inc. Annual Meeting of Stockholders to be Held on September 12, 2018

Under Securities and Exchange Commission rules, you are receiving this notice that the proxy materials for the annual shareholders’ meeting are available on the Internet. Follow the instructions below to view the materials and vote online or request a copy. The items to be voted on and location of the annual meeting are on the reverse side. Your vote is important!

This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. We encourage you to access and review all of the important information contained in the proxy materials before voting. The proxy statement, form of proxy, annual report to shareholders and directions to the annual meeting are available at:

	Easy Online Access — A Convenient Way to View Proxy Materials and Vote
	When you go online to view materials, you can also vote your shares.
	Step 1: Go to www.investorvote.com/NTCT.
	Step 2: Click on the icon on the right to view current meeting materials.
	Step 3: Return to the investorvote.com window and follow the instructions on the screen to log in.
	Step 4: Make your selection as instructed on each screen to select delivery preferences and vote.

When you go online, you can also help the environment by consenting to receive electronic delivery of future materials.

Obtaining a Copy of the Proxy Materials – If you want to receive a copy of these documents, you must request one. There is no charge to you for requesting a copy. Please make your request for a copy as instructed on the reverse side on or before 10 days before the meeting to facilitate timely delivery.

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Stockholder Meeting Notice

NetScout Systems, Inc. Annual Meeting of Stockholders will be held on September 12, 2018 at NetScout Systems, Inc., 310 Littleton Road, Westford, Massachusetts, at 10:00 a.m. local time.

Proposals to be voted on at the meeting are listed below along with the Board of Directors’ recommendations.

The Board of Directors recommends a vote FOR all nominees and FOR PROPOSALS 2, 3 AND 4:

1. To elect two Class I directors nominated by our Board to the Board of Directors to serve until the 2021 Annual Meeting of Stockholders or until their successors are duly elected and qualified.

01 - Alfred Grasso, 02 - Vincent J. Mullarkey

2. To approve the amendment and restatement of our 2011 Employee Stock Purchase Plan to increase the number of shares of our common stock authorized for issuance thereunder by 3,000,000 shares and make certain other changes described in Proposal 2 in the proxy materials.

3. To ratify the selection of PricewaterhouseCoopers LLP to serve as our independent registered public accounting firm for the fiscal year ending March 31, 2019.

4. To approve, on an advisory basis, the compensation of our named executive officers, as disclosed in the proxy statement in accordance with Securities and Exchange Commission rules.

Note: Your proxy holder will also vote on any other business properly brought before the Annual Meeting.

PLEASE NOTE – YOU CANNOT VOTE BY RETURNING THIS NOTICE. To vote your shares you must vote online or request a paper copy of the proxy materials to receive a proxy card. If you wish to attend and vote at the meeting, please bring this notice with you.

	Here’s how to order a copy of the proxy materials and select a future delivery preference: Paper copies: Current and future paper delivery requests can be submitted via the telephone, Internet or email options below. Email copies: Current and future email delivery requests must be submitted via the Internet following the instructions below. If you request an email copy of current materials you will receive an email with a link to the materials. PLEASE NOTE: You must use the number in the shaded bar on the reverse side when requesting a set of proxy materials.
	g Internet – Go to www.investorvote.com/NTCT. Follow the instructions to log in and order a copy of the current meeting materials and submit your preference for email or paper delivery of future meeting materials.
	g Telephone – Call us free of charge at 1-866-641-4276 and follow the instructions to log in and order a paper copy of the materials by mail for the current meeting. You can also submit a preference to receive a paper copy for future meetings.
	g Email – Send email to investorvote@computershare.com with “Proxy Materials NetScout Systems, Inc.” in the subject line. Include in the message your full name and address, plus the number located in the shaded bar on the reverse, and state in the email that you want a paper copy of current meeting materials. You can also state your preference to receive a paper copy for future meetings.
	To facilitate timely delivery, all requests for a paper copy of the proxy materials must be received by 10 days before the meeting.

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