<SEC-DOCUMENT>0001209191-20-027546.txt : 20200506
<SEC-HEADER>0001209191-20-027546.hdr.sgml : 20200506
<ACCEPTANCE-DATETIME>20200506190206
ACCESSION NUMBER:		0001209191-20-027546
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20200504
FILED AS OF DATE:		20200506
DATE AS OF CHANGE:		20200506

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Lin Geng
		CENTRAL INDEX KEY:			0001780599

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-26041
		FILM NUMBER:		20854037

	MAIL ADDRESS:	
		STREET 1:		C/O F5 NETWORKS, INC.
		STREET 2:		401 ELLIOTT AVE. WEST
		CITY:			SEATTLE
		STATE:			WA
		ZIP:			98119

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			F5 NETWORKS, INC.
		CENTRAL INDEX KEY:			0001048695
		STANDARD INDUSTRIAL CLASSIFICATION:	COMPUTER COMMUNICATIONS EQUIPMENT [3576]
		IRS NUMBER:				911714307
		STATE OF INCORPORATION:			WA
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		401 ELLIOTT AVENUE WEST
		CITY:			SEATTLE
		STATE:			WA
		ZIP:			98119
		BUSINESS PHONE:		2062725555

	MAIL ADDRESS:	
		STREET 1:		401 ELLIOTT AVENUE WEST
		CITY:			SEATTLE
		STATE:			WA
		ZIP:			98119

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	F5 NETWORKS INC
		DATE OF NAME CHANGE:	19990308

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	F5 LABS INC
		DATE OF NAME CHANGE:	19990305
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-05-04</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001048695</issuerCik>
        <issuerName>F5 NETWORKS, INC.</issuerName>
        <issuerTradingSymbol>FFIV</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001780599</rptOwnerCik>
            <rptOwnerName>Lin Geng</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O F5 NETWORKS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>801 5TH AVENUE</rptOwnerStreet2>
            <rptOwnerCity>SEATTLE</rptOwnerCity>
            <rptOwnerState>WA</rptOwnerState>
            <rptOwnerZipCode>98104</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP, Chief Technology Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2020-05-04</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>207</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>132.1586</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>590</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This transaction was executed pursuant to a Rule 10b5-1 trading plan, in multiple trades at prices ranging from $132.140000 to $133.101000. The reported price is the weighted average sale price. The reporting person undertakes to provide to the Company, any security holder of the Company, or Securities and Exchange Commission staff, upon request, complete information regarding the number of shares sold at each separate price.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Scot F. Rogers by Power of Attorney</signatureName>
        <signatureDate>2020-05-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
