#1◉ FORTINET. Investor Presentation December 2021#2Safe Harbor Statement W Information, statements and projections contained in these presentation slides concerning Fortinet's business outlook, the fourth quarter and full year 2021 guidance, and future prospects and expectations are forward-looking statements that involve risks and uncertainties. These forward-looking statements include statements regarding demand for our products and services, guidance and expectations around future financial results, including guidance and expectations for the fourth quarter and full year 2021, statements regarding the momentum in our business and future growth expectations, and statements regarding growth in market demand, the expansion of the total addressable market for network security, and leveraging our ASIC-supported security fabric platform. Although we attempt to be accurate in making forward-looking statements, it is possible that future circumstances might differ from the assumptions on which such statements are based such that actual results are materially different from our forward-looking statements in these presentation slides. Important factors that could cause results to differ materially from the statements herein include the following: general economic risks, including those caused by the COVID-19 pandemic; supply chain challenges which are significantly heightened in the current environment; negative impacts from the COVID-19 pandemic on sales, billings, revenue, demand and buying patterns, component supply and ability to manufacture products to meet demand in a timely fashion, and costs such as possible increased costs for shipping and components; global economic conditions, country-specific economic conditions, and foreign currency risks; competitiveness in the security market; the dynamic nature of the security market and its products and services; specific economic risks worldwide and in different geographies, and among different customer segments; uncertainty regarding demand and increased business and renewals from existing customers; uncertainties around continued success in sales growth and market share gains; actual or perceived vulnerabilities in our supply chain, products or services, and any actual or perceived breach of our network or our customers' networks; longer sales cycles, particularly for larger enterprise, service providers, government and other large organization customers; the effectiveness of our salesforce and failure to convert sales pipeline into final sales; risks associated with successful implementation of multiple integrated software products and other product functionality risks; risks associated with integrating acquisitions and changes in circumstances and plans associated therewith, including, among other risks, changes in plans related to product and services integrations, product and services plans and sales strategies; sales and marketing execution risks; execution risks around new product development and introductions and innovation; litigation and disputes and the potential cost, distraction and damage to sales and reputation caused thereby or by other factors; cybersecurity threats, breaches and other disruptions; market acceptance of new products and services; the ability to attract and retain personnel; changes in strategy; risks associated with management of growth; lengthy sales and implementation cycles, particularly in larger organizations; technological changes that make our products and services less competitive; risks associated with the adoption of, and demand for, our products and services in general and by specific customer segments, including those caused by the COVID-19 pandemic; competition and pricing pressure; product inventory shortages for any reason, including those caused by the COVID-19 pandemic; risks associated with business disruption caused by natural disasters and health emergencies such as earthquakes, fires, power outages, typhoons, floods, health epidemics and viruses such as the COVID-19 pandemic, and by manmade events such as civil unrest, labor disruption, international trade disputes, international conflicts, terrorism, wars, and critical infrastructure attacks; tariffs, trade disputes and other trade barriers, and negative impact on sales based on geo-political dynamics and disputes and protectionist policies; any political and government disruption around the world, including the impact of any future shutdowns of the U.S. government; and the other risk factors set forth from time to time in our most recent Annual Report on Form 10-K, our most recent Quarterly Report on Form 10-Q and our other filings with the Securities and Exchange Commission (SEC), copies of which are available free of charge at the SEC's website at www.sec.gov or upon request from our investor relations department. All forward-looking statements herein reflect our opinions only as of the date of these presentation slides, and we undertake no obligation, and expressly disclaim any obligation, to update forward-looking statements herein in light of new information or future events. O Fortinet, Inc. All Rights Reserved. 2#3Fortinet is the Only Pure Play Cybersecurity Company in the S&P 500 1 4 2 Large and fast-growing addressable market driven by long-term secular tailwinds 3 Proprietary ASIC technology and an integrated fabric platform lead to security anywhere in any form factor, driving growth into new markets Business model is highly diversified across geographies, customer segments, and industry verticals Recurring, high margin services revenue contributes to 'software-like' gross margins and sustainable free cash flow generation m II W O Fortinet, Inc. All Rights Reserved. 3#4Who We Are 20 Years of Strong Growth >$50B Market Cap (1) Nasdaq: FTNT Top 10 Performing S&P 500 Stock YTD (1) >$4.0B (+32% y/y) 2021E Billings (2) '21E Revenue of $3.3B+ (+29% y/y) (2 (2) W >$1.2B LTM Free Cash Flow (3) 40% Free Cash Flow Margin >75% Gross Margin (3) Recurring Service Revenues >25% Operating Margin (3) Balanced Growth and Profitability BBB+ & Baa1 Investment Grade Rating Leading the Cybersecurity Industry 8 Appearances in Gartner Magic Quadrants Leader in Network Firewalls & WAN Edge >35% Global Firewall Shipments (4) Most Deployed Network Security 1,200+ Issued Global Patents Industry Innovator Fortinet Has Been Profitable And Free Cash Flow (3) Positive Every Year Since Its IPO in 2009 Note: Data is as of December 31, 2020 unless otherwise noted. Based on the midpoint of 2021 guidance provided on November 4, 2021. (1) As of November 30, 2021. (2) (3) (4) © Fortinet, Inc. All Rights Reserved. Gross Margin, Operating Margin and Free Cash Flow are a non-GAAP financial measures. See Appendix for reconciliation of the non-GAAP financial measures to the most comparable GAAP financial measures. IDC Worldwide Quarterly Security Appliance Tracker, October 2021 (based on annual unit shipments of Firewall, UTM and VPN appliances).#5Consistent Execution - 'Rule of 40' Since 2009 IPO Achieved 'Rule of 40' 9 years out of the past 12 years and expect to achieve 'Rule of 50' in 2021 Rule of 40(1) m W 49% 58% 33% 24% 20% 14% 47% 24% 44% 41% 42% 34% 35% 19% 13% 15% 16% 47% 45% 43% 23% 25% 27% 17% ~55% 26% 19% 29% 34% 23% 15% 25% 31% 26% 17% 20% 20% 20% 29% (2) (2) (2) (2) 2009 2010 2011 2012 2013(2) (2) (2) (3) 2014 2015 2016 2017 2018 2019 2020 2021E ■Revenue Growth ■Non-GAAP Operating Margin Note: Fortinet's IPO was on November 18, 2009. (1) (2) (3) O Fortinet, Inc. All Rights Reserved. Fortinet defines the Rule of 40 and Rule of 50 as GAAP revenue Y/Y growth plus Non-GAAP Operating Margin. See Appendix for reconciliation of the non-GAAP financial measures to the most comparable GAAP financial measures. 2009-2015 have not been adjusted for an immaterial error related to the commencement of revenue recognition for certain FortiCare support service contracts. Based on the midpoint of 2021 guidance provided on November 4, 2021. 5#6Fortinet Secures Devices and Data Across Networks, Endpoints and Clouds FortiGate & Security Fabric Platform FortiGuard Security Services FortiCare Technical Support Services m W FORTIOS Fabric Management Center Adactive Cloud Security Driver Networking Ecosystem The Fort Guard Threat Intelligence Hardware and software spanning wide set of network security functions Global research team to identify and develop security solutions leveraging Al and automation 24/7/365 support and maintenance services O Fortinet, Inc. All Rights Reserved. 6#7Broad Global Footprint Burnaby Canada Sunnyvale US W ........ Ottawa Canada Sophia Antipolis France APAC 21% Herzliya Israel EMEA 23% Bangalore Uberlandia India Brazil 9,700 employees (1) 550,000+ customers worldwide (1) As of September 30, 2021 (Q3'21). O Fortinet, Inc. All Rights Reserved. Q3'21 Headcount (1) Headquarters Dev Centers FortiCare Support Centers Centers of Excellence Americas 56% 7#8Fortinet's CSR Impact Named one of the 100 Best ESG Companies of 2021 by Investor's Business Daily Environment Corporate HQ Winner of Silicon Valley Business Journal Structures Awards Corporate HQ on track for LEED Gold certification. Overall energy usage 30% lower than standard office building Corporate HQ solar panels makes the site net- zero energy and net-zero carbon All North American facilities run on renewable electricity Measured Scope 1 and 2 carbon emissions. Announced Commitment to Become Carbon Neutral by 2030 in alignment with Science Based Targets Initiatives (SBTi) Product energy efficiency is 3X to 16X higher than competition Fortinet Environmental Policy Social • Published Inaugural Diversity and Inclusion Report in 2021 • . Published 2020 EEO-1 Consolidated Employer Information Report • • . • Pledge to train 1 Million people to help close the cybersecurity skills Gap Established an Education Outreach Program to drive a diverse cyber workforce Free self-paced training courses Fortinet's cybersecurity curriculum part of the IBM Skills Build Program & Cyber Security Learning Hub in partnership with Salesforce and the WEF Partnered with Linksys to close the homework gap Publication of two books: Children's book to educate on Internet Security and guide for cyber leaders to improve cybersecurity strategies and foster diverse cyber talent • . Governance Social Responsibility Committee of the Board of Directors to promote long-term value for stakeholders. Amended bylaws to add annual election of all directors and allow shareholders to call a special meeting Added the ability for shareholders to place nominees for directors on the proxy ballot ("proxy access") Board of Directors is >50% racially diverse and 33% gender diverse Business Ethics: Screening 100% of new vendors from high-risk areas/countries and 100% of the Contract Manufacturers of Fortinet end products • • • W II • m O Fortinet, Inc. All Rights Reserved.#9Seasoned Management Team With 20+ Years Average Experience Ken Xie Chairman of the Board and CEO 25+ years of experience 20+ years with Fortinet (Founder) Michael Xie President and CTO 25+ years of experience 20+ years with Fortinet Keith Jensen CFO & CAO 30+ years of experience 7 years with Fortinet Patrice Perche CRO & EVP Support 30+ years of experience 16 years with Fortinet John Maddison CMO and EVP, Products 30+ years of experience 9 years with Fortinet m W Ana Pease VP, Talent Management and Operations 18+ years of experience 3 years with Fortinet John Whittle EVP, Corporate Development & General Counsel 20+ years of experience 15 years with Fortinet Sandra Wheatley Senior VP, Marketing and Threat Intelligence 20+ years of experience 6 years with Fortinet Peter Salkowski VP, Investor Relations 18+ years of experience 3 years with Fortinet O Fortinet, Inc. All Rights Reserved. 9#10Industry Growth Drivers . • • Industry Growth Drivers The Most Deployed Network Security Solution Cyberattacks are on the Rise Total Addressable Market m W#11Industry Growth Drivers Security Spending Increasing as a % of Total IT Budgets Security-Driven Networking Vendor Consolidation Heightened Awareness Networking and Security Converging . • Network infrastructure changes SD-WAN 5G and loT/OT SASE Micro-segmentation Edge / Cloud networking W II m Reducing Complexity Integrated solutions Reduce costs Lack of skilled security professionals . • Expanding Attack Surfaces Ransomware / high profile attacks . Colonial pipeline Sunburst Robinhood Work from anywhere Regulatory/compliance responsibilities . O Fortinet, Inc. All Rights Reserved. 11#12Fortinet - The Most Deployed Network Security Solution Over One-Third of All Firewall Shipments 40% m II W Unit Share IDC 35% 30% 25% 20% 15% 10% 5% 38% FORTINET. Cisco 14% Check Point 7% 4% Palo Alto Networks 0% 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 H1 O Fortinet, Inc. All Rights Reserved. Source: IDC Worldwide Security Appliance Tracker, October 2021 (based on annual unit shipments of Firewall, UTM, and VPN appliances). 12#13Cyberattacks are on the Rise $9M Average total data breach costs per incident in the U.S. (1) 87% of organizations are experiencing a shortfall of skilled IT security personnel % Of Organizations Compromised by at Least One Successful Cyberattack 86% $1.2M Average ransom demand, up 170% from H1'20 (2) 69% of organizations were compromised by ransomware Unique Ransomware Detections Per Week (3) >10x Increase June 2021 Weekly Average: ~149K m W 81% 78% 77% (1) (2) 2018 (3) Coalition Cyber Insurance Claims Report, H1 2021 Fortinet Global Threat Landscape Report, August 2021 Source: 2021 Cyberthreat Defense Report, CyberEdge Group, LLC, unless otherwise noted IBM Cost of a Data Breach Report 2021 2019 2020 2021 Average: ~14K July 2020 Weekly O Fortinet, Inc. All Rights Reserved. Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun 13#14A Large and Growing TAM: $174B+ by 2025 2021: $121B, 4-YR CAGR = ~10% Networking and Network Security Endpoint Security & Security Ops Identity & IoT/OT Security Cloud Security m W $86B 5G Network Firewall Switching Web (SASE) NPMD (NOC) Wireless SD-WAN IDPS $38B Threat Intel $25B SOAR SIEM VPN ZTNA loT/OT NAC Endpoint IAM Source: Fortinet estimates based on recent analyst research. 2025 opportunity shown. O Fortinet, Inc. All Rights Reserved. $25B WAF ADC CWPP SEG CASB 14#15Fortinet Growth Drivers . • • Fortinet Growth Drivers Security-Driven Networking Fortinet's OS and ASIC Advantage Magic Quadrants • Industry Consolidation Moving Up Market into Enterprise / G2000 m W#16Vendor Consolidation Heightened Awareness Increased Investments Fortinet Growth Drivers Security-Driven Networking Networking and Security Converging • ● • Network infrastructure changes Micro-segmentation Edge / Cloud networking W II m Reducing Complexity Security Fabric platform / hybrid cloud Expanding Attack Surfaces Ransomware/ high profile attacks Work from anywhere Regulatory/compliance responsibilities Investments to Support Growth Increased sales, marketing and channel investments R&D investments support organic growth • • Security Anywhere in Any Form Factor Lower TCO & Vendor Consolidation FORTINET. FortiASIC-CP9 1824QPF21 Hardware-based . • FortiOS / ASIC technology • + Increased presence with Global 2000 Proprietary technology lowers TCO FOS Software-based TCO Total Cost of Ownership O Fortinet, Inc. All Rights Reserved. 16#17Security-Driven Networking Convergence of Networking and Security m W Enterprise Networking At All Edges ((•)) Enterprise Security At All Edges Security Fabric Platform Broad. Integrated. Automated. Do NP7 Cloud Edge DC Edge LAN Edge Content Security Web Security User Security Zero Trust Access ← 360 FortiGuard Threat Intelligence WAN Edge LTE Edge OT Edge Device Security Advanced SOC/NOC Bundles Hardware, Software, SaaS Certified O Fortinet, Inc. All Rights Reserved. @ FORTIOS Fabric Management Center Adaptive Cloud Security Security-Driven Open Networking Ecosystem Network Operations Center Security Operations Center Open Ecosystem 17#18Fortinet's OS and ASIC Advantage FortiOS 7.0 OS FortiOS is the foundation of the Fortinet Security Fabric, consolidating many technologies and use cases into a simplified, single policy and management framework. Firewall (Gbps) System-on-a-Chip 4 (SoC4) FORTINET. FortiSPUTM-NP7 T6WYOSBG-0001 The System-on-a-Chip consolidates network and content processing, delivering fast application identification, steering, and overlay performance. SSL Inspection (Gbps) Content Processor 9 (CP9) Network Processor 7 (NP7) FORTINET. FortiASIC-CP9 1824QPF21 As a co-processor to the main CPU, Content Processors offload resource-intensive processing and drive content inspection to accelerate security functions. FORTINET Network Processors operate in-line to deliver unmatched performance for network functions and hyperscale for stateful firewall functions. W II m 95 Industry Avg 6x More 600 8x More FG 3500F 8 (1) Industry Avg 49 64 12x More Concurrent Sessions (M) 330 28 (1) (2) FG 3500F Industry Avg FG 3500F O Fortinet, Inc. All Rights Reserved. (1) Industry average benchmark is based upon similarly priced solutions from vendors that utilize generic processors for networking and security. Performance with hyperscale license applied. (2) 18#19Fortinet Appears in 8 Gartner Magic Quadrants Fortinet recognized as a Leader in 2 Magic Quadrants Network Firewalls WAN Edge Infrastructure Fortinet recognized as a Visionary in 2 Magic Quadrants Fortinet recognized as a Challenger or Niche in 2 Magic Quadrants Fortinet mentioned in 2 Magic Quadrants And Fortinet is listed in 8 Gartner Market Guides m W Gartner * ((•)) Wired and WLAN SIEM Web Application Firewall Secure Web Gateway Endpoint Protection Platforms Indoor Location Services EDR IDPS Email NAC NDR ZTNA OT SOAR O Fortinet, Inc. All Rights Reserved. 19#20Network Firewalls and WAN Edge (SD-WAN) Leader 2021 Magic Quadrant for Network Firewalls CHALLENGERS LEADERS 2021 Magic Quadrant for WAN Edge Infrastructure CHALLENGERS LEADERS m W ABILITY TO EXECUTE Alibaba Cloud Microsoft Huawei Juniper Amazon Web Services H3C WatchGuard SonicWall NICHE PLAYERS COMPLETENESS OF VISION Source: Gartner (November 2021) Cisco Palo Alto Networks Fortinet Check Point Software Technologies Hillstone Networks Sophos Forcepoint Barracuda Sangfor Versa Networks Cato Networks VISIONARIES As of August 2021 Gartner, Inc Fortinet Recognized as a Leader ABILITY TO EXECUTE Fortinet VMware Versa Networks Palo Alto Networks Huawei Cisco Citrix HPE (Aruba and Silver Peak) Nuage Networks Cradlepoint Peplink Juniper Networks Barracuda Fat Pipe Networks Riverbed NICHE PLAYERS VISIONARIES COMPLETENESS OF VISION As of September 2021 Ⓒ Gartner, Inc Gartner Source: Gartner (September 2021) Fortinet Recognized as a Leader O Fortinet, Inc. All Rights Reserved. This graphic was published by Gartner, Inc. as part of a larger research document and should be evaluated in the context of the entire document. The Gartner document is available upon request from Fortinet. Gartner does not endorse any vendor, product or service depicted in its research publications, and does not advise technology users to select only those vendors with the highest ratings or other designation. Gartner research publications consist of the opinions of Gartner's research organization and should not be construed as statements of fact. Gartner disclaims all warranties, expressed or implied, with respect to this research, including any warranties of merchantability or fitness for a particular purpose. 20 20#21$ In Millions Fragmented Industry Ready for Consolidation $5,000 $4,500 $4,000 $3,500 Fortinet $3,000 $2,500 $2,000 $1,500 $1,000 $500 $0 60 LTM Reported Revenue SentinelOne W I Palo Alto Networks Fortinet m NortonLifeLock McAfee Splunk Check Point O Fortinet, Inc. All Rights Reserved. Note: Top 20 pure play cybersecurity companies by market cap listed on the NYSE and NASDAQ as of December 1, 2021 shown. Source: Nasdaq IR Insight and SEC filings. CrowdStrike Okta Zscaler Elastic Mandiant Cloudflare Mimecast Tenable Rapid7 CyberArk SailPoint Qualys Varonis 21 21#22Moving Up Market into Enterprise / G2000 425 147 278 W Deal Count Over $500K 582 639 602 213 228 434 $300 145 426 374 289 2018 2019 2020 ■Deals Over $500K Q3'20 YTD Deals Over $1M Q3'21 YTD II m (1) Excludes Telco. Billings data is derived from invoiced amounts. $ In Millions Billings for Deals Over $1M (1) $392 $445 $305 $460 2018 2019 2020 Q3'20 YTD Q3'21 YTD O Fortinet, Inc. All Rights Reserved. 22 22#23Financial Overview . Billings • Income Statement • Balance Sheet and Cash Flow • Financial Guidance m W#24Billings . • • • Total Billings FortiGate and Non-FortiGate Fabric Billings Key Non-FortiGate Solutions Highly Diversified Business Model Secure SD-WAN Billings m W#25Billings Growth Accelerating to -32% Y/Y in 2021 Service Billings Account for ~69% of Total Billings $ in Millions m W $2,153 $674 $1,479 2018 -69% +32% y/y ~$4,065 CAGR (2018 to 2021E) Services 24% Products 23% 24% CAGR $3,090 ~$1,250 $2,603 2019 Service Billings $916 I I ~$2,815 -69% $2,174 2020 Product Revenue (1) 2021E (1) Based on the midpoint of 2021 guidance provided on November 4, 2021. O Fortinet, Inc. All Rights Reserved. Note: Total Billings is a non-GAAP financial measure, further categorization is derived from invoiced amounts. See Appendix for reconciliation of the non-GAAP financial measure to the most comparable GAAP financial measure. 25 25#26FortiGate and Non-FortiGate Fabric Billings $1B+ Non-FortiGate Business in 2021 $ in Millions W II m $2,153 2018 25% 24% CAGR $2,603 $3,090 +39% y/y 28% ~$4,065 CAGR (2018 to 2021E) Non-FG Fabric 39% +~44% y/y -30% FortiGate 21% (1) 2019 2020 2021E FortiGate Non-FG Fabric Non-FG Other 2018 2-YR 2020 CAGR Cloud $124M Non-FG Fabric $276M $237M $505M 38% 35% O Fortinet, Inc. All Rights Reserved. (1) Based on the midpoint of 2021 guidance provided on November 4, 2021. 2021E FortiGate and Non-FortiGate split based on Q3'21 YTD percentages. Note: Total Billings is a non-GAAP financial measure, further categorization is derived from invoiced amounts. See Appendix for reconciliation of the non-GAAP financial measure to the most comparable GAAP financial measure. 26#27Infrastructure Solution Cloud Fabric Non-FG Q3'21 LTM Billings Growth Rates Forti- Analyzer HW Cloud Top 10 = 48% y/y Total = 43% y/y Client/EDR SW Cloud GateVM SW Cloud Mail HW Cloud Manager HW Cloud Sandbox HW/SW Cloud Secure AP HW Secure Switch HW Transceiver HW Web HW Cloud Top 10 Non-FortiGate Solutions Top 10 Solutions Represented ~70% of Non-FG LTM Billings Fabric m II W Note: Hardware includes hardware appliances. Software includes software licenses and SaaS subscriptions. O Fortinet, Inc. All Rights Reserved. 27 27#28Highly Diversified Business Model Across Customer Segments, Geographies and Industries Customer Segments LTM Billings – Q3'21 ($3,837M) - Geographies W II m 26% 26% 48% Enterprise and SP/MSSP SMB ■Mid-Enterprise Industries 9% 10% 26% 100+ Other Industries Countries 12% 38% 49% United States Japan Germany Canada France United Kingdom Note: Billings data is derived from invoiced amounts. O Fortinet, Inc. All Rights Reserved. 14% 17% ■Government Financial Services SP/MSSP ■Technology ■Retail/Hospitality 28 88#29Secure SD-WAN Billings are Growing Rapidly SD-WAN Represented ~14% of Total Billings for Q3'21 YTD W II m $ in Millions ~1% $32 11x Growth ~7% $178 2018 2019 ~11% $355 2020 ~11% $230 +71% ~14% $394 Q3'20 YTD Q3'21 YTD ■SD-WAN Billings % of Total Billings O Fortinet, Inc. All Rights Reserved. Note: Billings data is derived from invoiced amounts. 29 29#30Income Statement . Strong Revenue Growth at Scale • • • • • • Consistent Revenue Growth by Geo Consistent Execution Product and Total Revenue vs. Closest Competitor Improving Product and Service Gross Profit Gross and Operating Margins Sales Leverage and Expense Discipline Drive Margin Growth Peer Performance m W#31W Strong Revenue Growth at Scale Revenue Growth Acceleration in 2021, Predictable Service Revenue Accounts for ~63% of Revenue II m $ In Millions $1,805 $674 $1,130 2018 63% Total Revenue ~$3,335 23% CAGR CAGR (2018 to 2021E) $2,594 Services 23% $2,163 -$1,250 +36% y/y Products 23% $916 -63% $1,678 -$2,085 +24% y/y (1) 2019 2020 2021E ■Service Product (1) Based on the midpoint of 2021 guidance provided on November 4, 2021. O Fortinet, Inc. All Rights Reserved. 31#32$ in Millions m W Q3'18 Consistent Revenue Growth by Geo Quarterly Revenue by Region $350 CAGR (Q3'18 to Q3'21) $323 $272 Americas 22% $241 EMEA 25% $243 APAC 27% $194 $194 $201 $135 $165 $106 $94 Q3'19 Q3'20 -Americas EMEA -APAC O Fortinet, Inc. All Rights Reserved. Q3'21 32 32#33W II m +2% -2% Drivers of Consistent Revenue Performance Q3'18 Q3'19 Discount Rate (1) +2% Renewal Rate (1) -2% Q3'18 Q3'19 (1) Compared to +/- 2% of the 3-year trailing average. Q3'20 Q3'20 Q3'21 Q3'21 Q3'18 Q3'18 O Fortinet, Inc. All Rights Reserved. Q3'19 Average Contract Term 30 mo. Q3'20 Avg Contract Term Avg Contract Term Excl SD-WAN Percentage of Service Revenue from Deferred (1) Q3'19 Q3'20 Q3'21 33 Q3'21 +2% -2% 24 mo.#34W $ in Millions $751 Q3'19 Product and Total Revenue Growth vs. PANW M&A Activity(1): FTNT = $157M; PANW = $1,776M LTM Product Revenue LTM Total Revenue $1,087 Q3'20 2-YR CAGR $1,179 FTNT = 25% PANW = 4% $1,070 $867 FTNT PANW Q3'21 $1,165 $ in Millions Q3'19 $3,016 $2,054 Fortinet, Inc. All Rights Reserved. (1) Total purchase price of acquisitions per SEC filings based on transactions that closed from October 1, 2019 through September 30, 2021 for FTNT and November 1, 2019 through October 31, 2021 for PANW. Note: PANW's fiscal year does not follow the calendar year. As such, PANW's calendar Q3'21 LTM results are calculated using the following fiscal quarters: Q2'21, Q3'21, Q4'21, and Q1'22. Q3'20 2-YR CAGR FTNT = 23% PANW=23% $3,583 $2,465 -FTNT -PANW Q3'21 34 $4,558 $3,127#35Improving Product and Service Gross Profit Multiple High-Margin Service Contracts Attach to Core Products $ in Millions W II m $1,373 $391 $982 72% 2018 ~$2,568 I 23% CAGR | $2,048 I | | 1 I $1,678 | $570 I I 1 I | Product Gross Profit | | I | Service Gross Profit I | I $1,478 72% 1 I | | I 2019 2020 2021E (1) O Fortinet, Inc. All Rights Reserved. (1) Based on the midpoint of 2021 revenue and gross margin guidance provided on November 4, 2021. The calculated gross profit guidance is $2,540M at the low-end and $2,596M at the high-end. Note: All data on the provided slide are Non-GAAP. Non-GAAP Gross profit is a non-GAAP financial measure. See Appendix for reconciliation of the non-GAAP financial measures to the most comparable GAAP financial measures. 55 35#36Software-Like Gross Margins Drives Strong Operating Performance m W Gross Margin Operating Margin 2021E Margins Impacted by Acquisitions and a Revenue Mix Shift of ~215 bps Towards Product vs. 2020 78.9% 77.6% 77.0% 78.0% 76.1% 76.6% 26.9% 26.0% 24.8% 22.5% 20.5% 16.2% 13.1% 75.0% 2018 2019 2020 2021E(1) 2018 2019 2020 2021E (2) -GAAP -Non-GAAP GAAP -Non-GAAP (2) (1) Based on the midpoint of 2021 guidance provided on November 4, 2021. (2) © Fortinet, Inc. All Rights Reserved. Non-GAAP gross margin and non-GAAP operating margin are non-GAAP financial measures. See Appendix for reconciliation of the non-GAAP financial measures to the most comparable GAAP financial measures. 36 36#37W Fortinet Leads Palo Alto Networks and Cybersecurity Peers in Operating Margins GAAP Operating Margin Non-GAAP Operating Margin 27.4% 18.4% 19.5% 26.5% 19.2% 21.7% 15.8% 16.2% 8.8% (4.7%) (6.7%) (6.6%) LTM SBC as a LTM HC % of Revenue Increase (10.6%) FTNT 7% 20% (13.5%) (17.9%) PANW 21% 32% Peer Average 30% 52% Q3'19 II m Q3'20 -FTNT -PANW Peer Average (1) Q3'21 Q3'19 Source: Company filings. O Fortinet, Inc. All Rights Reserved. (1) Peer average is revenue-weighted and is composed of the following companies: Palo Alto Networks, CrowdStrike, Okta, and Zscaler. Note: PANW's fiscal year does not follow the calendar year. Q3'20 -FTNT PANW Peer Average (1) 25.8% 18.0% 13.1% Q3'21 37#38Sales Leverage and Expense Discipline Drive Margin Growth 54% 4% Non-GAAP Operating Expenses as a % of Revenue 53% 52% 4% ~51% W II m 12% 38% 2018 11% I I I I 2018-2021E CAGR Revenue = 23% Opex = 21% Q3'21 Headcount Mix (2) 6% G&A I 19% Services & Ops 53% I 37% I S&M I 22% R&D 2019 2020 ■ S&M ■R&D G&A 2021E (1) (1) Based on the midpoint of 2021 guidance provided on November 4, 2021. (2) As of September 30, 2021 (9,700 employees). O Fortinet, Inc. All Rights Reserved. Note: S&M, R&D and G&A are non-GAAP and exclude stock-based compensation and amortization of acquired intangible assets. See Appendix for reconciliation of the non-GAAP financial measures to the most comparable GAAP financial measures. 38 38#39Revenue Growth and Non-GAAP Operating Margin vs. Cybersecurity Peers 35% 30% 25% 20% Non-GAAP Operating Margin W 15% 10% II m 5% 0% -5% -10% 0% 10% 20% Data based off most recently reported quarter as of December 1, 2021. Source: Company filings Fortinet CrowdStrike Palo Alto Networks Zscaler 30% 40% 50% Y/Y Revenue Growth Area of circle illustrates latest reported quarter's revenue O Fortinet, Inc. All Rights Reserved. Okta 60% 70% 80% 39#40Balance Sheet and Cash Flow . • • DSO and Cash Balance Deferred Revenue and Free Cash Flow Investments and Capital Allocation m W#41W II m Q4'18 Declining DSO's and Increased Cash Balance Days Sales Outstanding (DSO) Cash Balance (1) $1.0B Debt Offering - Investment Grade Rating 79 Q4'19 (1) Cash and cash equivalents and short-term investments. 79 Q4'20 87 Q3'21 63 $ In Billions Q4'18 O Fortinet, Inc. All Rights Reserved. 2020: Repurchased $1.1B of FTNT shares - 11.7M shares $1.6 $2.1 Q4'19 Q4'20 $1.8 Q3'21 $3.1 41#42W II m Growing Deferred Revenue and Free Cash Flow Service Contracts Generating Free Cash Flow Deferred Revenue Free Cash Flow (1) (1) $ In Millions $1,667 $712 25% CAGR $2,109 $955 $3,106 $2,605 $1,490 $1,616 $ In Millions $908 $716 $586 $644 35% 35% 33% 32% $988 42% 2018 2019 2020 Q3'21 2018 2019 ■Current Def Rev Non-Current Def Rev 2020 Free Cash Flow Margin Q3'20 YTD Q3'21 YTD O Fortinet, Inc. All Rights Reserved. Free Cash Flow and Free Cash Flow Margin are non-GAAP financial measures. See Appendix for reconciliation of the non-GAAP financial measure to the most comparable GAAP financial measure. 42#43Strategic Investments and Capital Allocation Focused on Internally Building an Integrated Platform and Total Shareholder Return Innovation: ~$1.4B since 2017 $1.2B spent on R&D (1) Capital Return: ~$2.3B since 2017 Repurchased 29.4M Shares for $2.1B (2) W II m (1) (2) M&A 13% R&D 87% M&A 8% Share Repurchases 92% O Fortinet, Inc. All Rights Reserved. This represents our non-GAAP research and development expense from January 1, 2017 through September 30, 2021. See Appendix for reconciliation of the non-GAAP financial measure to the most comparable GAAP financial measure. Shares repurchased from January 1, 2017 through September 30, 2021. 43#44Financial Guidance . Guidance for Q4'21 and 2021 Key Takeaways m W#45Guidance for Q4'21 and 2021 Q4'20 Actual Q4'21 Guidance 2020 Actual 2021 Guidance Billings $960.9M $1.165-$1.215B $3.090B $4.040 - $4.090B Y/Y Mid-Pt Growth 23.8% 31.6% Revenue (GAAP) $748.0M $940 - $970M $2.594B $3.320-$3.350B Y/Y Mid-Pt Growth 27.7% 28.6% Service Revenue (GAAP) $459.6M $1.678B $2.080 - $2.090B Y/Y Mid-Pt Growth 24.3% Gross Margin 78.5% 75.0 - 76.0% 78.9% 76.5 - 77.5% Operating Margin 29.4% 27.0 - 28.0% 26.9% 25.5 - 26.5% Earnings per share $1.06 $1.10 - $1.15 $3.35 $3.85 - $3.95 As of November 4, 2021 m II W O Fortinet, Inc. All Rights Reserved. Note: Amounts above are non-GAAP except where GAAP is noted. Our guidance with respect to non-GAAP financial measures excludes stock-based compensation and amortization of acquired intangible assets. We have not reconciled our guidance with respect to non- GAAP financial measures to the corresponding GAAP measures because certain items that impact these measures are uncertain or out of our control, or cannot be reasonably predicted. Accordingly, a reconciliation of these non-GAAP financial measures to the corresponding GAAP measures is not available without unreasonable effort. 45#46Additional Modeling Points As of November 4, 2021 W II Cash Paid for Taxes Capital Expenditures Non-GAAP Tax Rate m Shares Outstanding Q4'21 Guidance 2021 Guidance $170 - $190M ~$130M $315 $335M - 21% 21% 168 - 170M 167-169M O Fortinet, Inc. All Rights Reserved. Note: In order to provide a more complete picture of our recurring core business operating results, we include in non-GAAP net income and non-GAAP diluted net income per share, the tax adjustment required resulting in an effective tax rate on a non-GAAP basis, which often differs from the GAAP tax rate. 46#47Key Takeaways Cybersecurity TAM is $174B+ (1) Fortinet is an Industry Leader Diversified Revenue Base Predictable, Recurring Service Revenue Expanded into new markets such as SASE, ZTNA, Cloud, and 5G Proprietary ASIC technology and integrated FortiOS platform which allows Fortinet to provide security across all attack surfaces from data center to endpoint to cloud Diversified across geographies, customer sizes, and industry verticals drives revenue visibility Contributes to 'software-like' margins, driving sustainable free cash flow generation W II m (1) Based on 2025E TAM. O Fortinet, Inc. All Rights Reserved. 47#48Appendix . • • • • Product Diagram FortiSASE Product Offering Non-FortiGate Products Performance vs. Peers Non-GAAP Reconciliations m W#49Digital Security, Everywhere You Need It FortiGuard Security Services Fabric Management Center - SOC m W SOC & NOC ום User Security Endpoint Breach Fabric Management Center NOC Open Ecosystem Incident Response Content Security User Security FortiSandbox 景 FortiAnalyzer FortiSIEM FortiEDR Web Security Device Security FortiDeceptor 回 Advanced SOC/NOC Zero Trust Access FortiManager Connector Fabric API FortiCloud Bundled Security FortiAl FortilSOAR FortiXDR FortiGuard MDR Service √ FortiMonitor 1 Security-Driven Networking LAN Edge WAN Edge DC Edge Cloud Edge Network ((•)) III III 8 DevOps Extended Fabric Ecosystem Adaptive Cloud Security Platform Applications FortiClient FortiNAC FortiVoice FortiAP FortiGate SD-WAN FortiGate FortiSASE FortiGate VM Cloud Networking FortiCASB FortiCWP FortiWeb FortiMail 384629 FortiToken ខ 4 ४ aws Microsoft Azure FortiAuthenticator FortiCamera FortiSwitch FortiExtender FortiProxy FortilSolator FortiDDos FortiSegment AWS Native Azure Native FortiADC | | Appliance VM Hosted Cloud O Fortinet, Inc. All Rights Reserved. Software Container go FortiGSLB 49#50FortiSASE Product Offering Cloud-Native Security for All Access Edges Digital Experience Monitoring Application aaS |IIII ||||| Data Center E.III E laaS SaaS Network aaS Peering √ Monitoring FortiCASB • Enterprise Class Security Security aaS m W • Flexible Edge Access FortiGate SD-WAN NGFW Web Gateway Secure Integrated ZTNA FortiSASE Secure Edge O Fortinet, Inc. All Rights Reserved. FortiExtender FortiClient FortiSASE Thin Edge FortiSASE SIA 50#51Key Non-FortiGate Solutions Fabric Fabric Infrastructure Infrastructure Cloud Solution Cloud Solution Fabric Fabric Cloud Security Management Center NOC & SOC Forti- Cloud Cloud Forti- Analyzer HW Cloud GateVM SW Cloud Cloud Cloud Mail HW Cloud EDR SW Cloud SASE(1) Cloud Manager HW Cloud Web HW Cloud Monitor (1) Cloud Zero Trust Access Portal Cloud Forti- Authenticator HW Cloud Sandbox HW/SW Cloud Client SW Cloud SOAR SW Cloud NAC HW/SW Cloud Token HW/SW Cloud SIEM Secure Access HW/SW Cloud Forti- AP HW Extender HW Switch HW m II W O Fortinet, Inc. All Rights Reserved. Note: The above is not an inclusive list of all Fabric & Cloud Solutions. Also excluded is Other Products which includes Professional Services and Training. (1) 2020 Acquisition. 51#52List of Non-FortiGate Products FORTIDIRECTOR FORTISCAN m W ALIBABA CLOUD AMAZON WEB SERVICE FORTIDNS ASCENLINK AZURE CLOUD SERVICE CYBERSPONSE ENSILO FORTIEDR FORTIEXPLORER FORTIEXTENDER FORTIFONE FORTISIEM FORTISMS FORTISOAR FORTISWITCH EXCLUDING 5000 SERIES FORTITAP FORTITESTER FORTITOKEN FAMS FORTIGATE-ONE FNDN FORTIGATEVM FORTIADC FORTIGATEVOICE FORTIVOICE FORTIAI FORTIGUARD PREMIER SERVICE FORTIWAN FORTIANALYZER FORTIGUARDVOICE FORTIWEB FORTIAP FORTIHYPERVISOR FORTIWIFIVOICE FORTIAP-U FORTIAUTHENTICATOR FORTIBALANCER FORTIBRIDGE FORTIINSIGHT FORTIISOLATOR FORTIMAIL FORTIMANAGER FORTIWLC FORTIWLM GOOGLE CLOUD PLATFORM MERU MODULE FORTIMOM-VM FORTIMONITOR MSSP FORTICACHE FORTICALL FORTICAMERA FORTICLIENT FORTICLOUD FORTICONVERTER FORTICORE FORTIDB FORTIDDOS FORTIDECEPTOR FORTINAC FORTIPORTAL FORTIPRESENCE FORTIPROXY FORTIRECORDER FORTIREPORTER FORTISANDBOX FORTISASE © Fortinet, Inc. All Rights Reserved. OPAQ ORACLE CLOUD INFRASTRUCTURE OTHER TALKSWITCH TRAINING TRANSCEIVER VIRTUAL DOMAIN LICENSE 52#53Reconciliation of Non-GAAP Results to GAAP Results m W $ in millions Total revenue Add change in deferred revenue Add deferred revenue adjustment due to adoption of the new revenue recognition standard Less deferred revenue balance acquired in business acquisition Total Billings $ in millions GAAP gross profit Stock-based compensation Amortization of acquired intangible assets Non-GAAP gross profit Non-GAAP gross margin 2018 $1,804.6 $2,163.0 2019 2020 $2,594.4 LTM Q3'21 $3,126.6 347.1 442.3 496.2 714.4 4.1 (2.5) (2.4) $2,153.3 $2,602.9 (0.6) (4.5) $3,090.0 $3,836.5 2018 $1,354.2 2019 $1,657.1 2020 $2,024.4 12.3 12.8 14.5 6.2 $1,372.7 76% 7.7 $1,677.6 78% 9.1 $2,048.0 79% © Fortinet, Inc. All Rights Reserved. 53#54Reconciliation of Non-GAAP Results to GAAP Results m W $ in millions 2018 GAAP product gross profit $383.4 2019 $463.9 2020 $564.0 Stock-based compensation 1.5 1.5 1.6 Amortization of acquired intangible assets 6 6.5 4.7 Non-GAAP product gross profit $390.9 $471.9 $570.3 Non-GAAP product gross margin 58.0% 59.9% 62.2% $ in millions 2018 2019 2020 GAAP service gross profit $970.8 $1,193.2 $1460.4 Stock-based compensation 10.8 11.3 12.9 Amortization of acquired intangible assets 0.2 1.2 4.4 Non-GAAP service gross profit $981.8 $1,205.7 1,477.7 Non-GAAP service gross margin 86.9% 87.7% 88.1% O Fortinet, Inc. All Rights Reserved. 54#55Reconciliation of Non-GAAP Results to GAAP Results m W $ in millions 2018 2019 2020 GAAP sales and marketing expense Stock-based compensation $782.3 $926.9 $1,071.9 (95.6) (101.7) (108.4) Amortization of acquired intangible assets (2.8) (3.2) (4.2) Non-GAAP sales and marketing expense $683.9 $822.0 $959.3 $ in millions 2018 2019 2020 GAAP general and administrative expense $93.0 $102.1 $119.5 Stock-based compensation (18.6) (20.9) (23.3) Litigation-related matter 0.7 Non-GAAP general and administrative expense $74.4 $81.2 $96.9 $ in millions 2017 2018 2019 2020 Q3'21 YTD GAAP research and development expense $210.6 $244.5 $277.1 $341.4 $311.6 Stock-based compensation (32.2) (36.4) (38.7) (47.6) (42.0) Non-GAAP research and development $178.4 $208.1 $238.4 $293.8 $269.6 expense © Fortinet, Inc. All Rights Reserved. 55#56Reconciliation of Non-GAAP Results to GAAP Results m W $ in millions 2018 2019 2020 Q3'19 Q3'20 Q3'21 GAAP operating income $234.4 $351.0 $531.8 $100.6 $126.9 $166.4 GAAP operating margin 13% 16% 21% 18.4% 19.5% 19.2% Stock-based compensation 162.9 174.1 193.8 42.4 50.0 53.5 Amortization of acquired intangible assets 9.0 10.9 13.3 2.2 2.8 4.8 Litigation settlement expenses (0.7) Gain on IP matter (40.2) (1.1) (1.1) Non-GAAP operating income $406.3 $536.0 Non-GAAP operating margin 23% 25% $698.0 27% $145.2 $178.6 $223.6 26.5% 27.4% 25.8% O Fortinet, Inc. All Rights Reserved. 56 56#57Reconciliation of Non-GAAP Results to GAAP Results $ in millions 2009 (1) 2010 (1) 2011 (1) 2012 ( 2(1) 2013 (1) 2014 (1) 2015 (1) 2016 2017 2018 2019 2020 GAAP operating income GAAP operating margin $25.3 $55.3 $88.9 $100.5 10% 17% 21% $72.1 $59.3 $14.9 $46.0 $112.6 $234.4 $351.0 $531.8 19% 12% 8% 1% 4% 8% 13% 16% 20% Stock-based compensation 7.4 9.3 19.0 30.7 44.4 59.0 95.0 122.4 137.2 162.9 174.1 193.8 Amortization of acquired intangible assets 1.6 1.4 3.1 9.3 8.6 9.0 10.9 13.3 Impairment of intangible assets 0.5 2.4 1.6 Write-off of intangible asset 2.4 ERP-related expenses W m II Acquisition-related charges Restructuring charges Inventory fair value adjustment amortization Litigation settlement expenses Gain on IP matter Non-GAAP operating income Non-GAAP operating margin $35.1 14% 5.4 13.4 2.7 0.3 I 7.6 4.0 0.3 2.9 0.8 (1.9) (1.9) (1.9) 1.5 (0.7) (40.2) $64.6 $106.0 $129.3 $116.7 $122.1 $133.2 $196.2 $260.2 $406.3 $536.0 $698.0 20% 24% 24% 16% 15% 17% 23% 25% 27% 19% 13% O Fortinet, Inc. All Rights Reserved. 2009-2015 have not been adjusted for an immaterial error related to the commencement of revenue recognition for certain FortiCare support service contracts. 57#58Reconciliation of Free Cash Flow m W $ in millions Net cash provided by operating activities. Less purchases of property and equipment 2018 2019 $638.9 $808.0 $1,083.7 2020 LTM Q3'21 Q3'20 YTD Q3'21 YTD $1,429.4 $787.2 $1,132.9 Less proceeds from IP matter (53.0) (92.2) (125.9) (50.0) (176.9) (93.6) (144.6) (50.0) Free cash flow Free cash flow Margin $585.9 $715.8 $907.8 $1,252.5 $643.6 $988.3 32% 33% 35% 40% 35% 42% O Fortinet, Inc. All Rights Reserved. 58#59FÖRTINET.