Objective 3.2Medium10 min

SD-WAN and SASE

Software-defined wide area networking and Secure Access Service Edge. Covers modern approaches to distributed network security, SD-WAN benefits and security, SASE architecture, and zero trust network access.

Understanding SD-WAN and SASE

Traditional WANs route all traffic through corporate data centers, creating bottlenecks as cloud adoption grows. SD-WAN and SASE represent modern approaches to distributed network security that put security controls closer to users and cloud resources.

Modern networking evolution:Traditional WAN — MPLS, traffic through data center • SD-WAN — Software-defined, intelligent routing • SASE — Security + networking converged in cloud

Gartner predicts that by 2025, 80% of enterprises will have adopted SASE architecture. This shift recognizes that with cloud applications and remote workers, the traditional perimeter has dissolved—security must follow users and data everywhere.

Understanding SD-WAN and SASE is essential for modern network security architecture.

Why This Matters for the Exam

SD-WAN and SASE are increasingly tested on SY0-701 as organizations modernize their networks. Questions cover the benefits, security components, and appropriate use cases.

Understanding these technologies helps with network architecture, cloud security, and remote workforce protection. Traditional perimeter security doesn't work for distributed environments.

The exam tests conceptual understanding of these modern approaches and when to apply them.

Deep Dive

What Is SD-WAN and How Does It Differ from Traditional WAN?

Traditional WAN vs SD-WAN:

Traditional WAN vs SD-WAN
Traditional (MPLS)
Branch
MPLS only
Data Center
all traffic backhauled
Cloud/Internet
✗ High cost, poor cloud perf
SD-WAN
Branch
direct
tunnel
Cloud
DC
✓ Lower cost, direct cloud
SD-WAN: Multiple transport, intelligent routing, direct cloud access

SD-WAN Benefits:

BenefitDescription
Cost savingsUse broadband instead of expensive MPLS
PerformanceDirect cloud access, intelligent routing
AgilityRapid deployment, centralized management
RedundancyMultiple transport paths
VisibilityApplication-aware traffic management

SD-WAN vs Traditional WAN:

AspectTraditional WANSD-WAN
TransportMPLS (expensive)Multiple (MPLS, broadband, LTE)
Cloud accessBackhauledDirect
DeploymentComplexRapid
ManagementPer-deviceCentralized
VisibilityLimitedApplication-aware

What Security Features Does SD-WAN Include?

SD-WAN Security Components:

FeatureFunction
EncryptionTunnel encryption between sites
SegmentationTraffic isolation by application/user
FirewallIntegrated stateful inspection
Application identificationClassify and control apps
Threat intelligenceBlock known bad destinations

SD-WAN Security Considerations:

ConsiderationWhy Important
Direct internet accessBypasses central security
Multiple pathsConsistent policy enforcement
Cloud integrationSecure cloud connectivity
Management planeProtect centralized controller

Addressing Direct Internet Access:

Option 1: Local security stack at each site
Option 2: Cloud-based security (SASE)
Option 3: Backhaul security traffic only

What Is SASE and What Components Does It Include?

SASE (Secure Access Service Edge) combines networking and security in a cloud-delivered service.

SASE Architecture:

SASE Architecture
Branches
Remote Users
SASE Cloud PoP
FWaaS
SWG
CASB
ZTNA
DLP
SD-WAN
Cloud Apps
Data Center
Network + Security converged • Cloud-delivered • Consistent policy everywhere

SASE Components:

ComponentFunction
SD-WANIntelligent routing and optimization
FWaaSFirewall as a Service
SWGSecure Web Gateway
CASBCloud Access Security Broker
ZTNAZero Trust Network Access
DLPData Loss Prevention

SASE Benefits:

BenefitDescription
Unified platformSingle vendor for network + security
Cloud-deliveredNo hardware to manage
Global coveragePoPs worldwide for low latency
ScalabilityElastic cloud resources
Consistent policySame security everywhere

What Is Zero Trust Network Access (ZTNA)?

ZTNA replaces traditional VPN with identity-based, application-specific access.

Traditional VPN vs ZTNA
Traditional VPN
[User authenticates][Full network access]Access to everything on network
ZTNA
[User authenticates][Specific app access only]No network access, just the app
ZTNA = Never trust, always verify • Smaller attack surface

ZTNA vs VPN:

AspectVPNZTNA
Access scopeFull networkSpecific applications
Trust modelImplicit trust once connectedNever trust, always verify
Attack surfaceLarge (whole network)Small (single app)
User experienceConnect to networkConnect to app
ScalabilityHardware limitedCloud-native

How Does SASE Compare to Traditional Architecture?

Traditional vs SASE Architecture
Traditional
Branch → MPLS → Data CenterSecurity StackInternet → Cloud AppsAll traffic through DC = bottleneck
SASE
Branch → SASE PoP → CloudRemote → SASE PoP → DCSecurity at edgeDirect cloud access
SASE: Security follows users, not the other way around

Architecture Comparison:

AspectTraditionalSASE
Security locationData centerCloud edge
Cloud accessBackhauledDirect
Remote usersVPN to DCZTNA to apps
ScalabilityAdd hardwareCloud elastic
ManagementMultiple toolsSingle platform

How CompTIA Tests This

Example Analysis

Scenario: A company has 50 branch offices and 2,000 remote workers. Currently, all traffic routes through the data center via MPLS, causing poor performance for cloud applications. They need improved cloud app performance, consistent security for all users, and reduced WAN costs.

Analysis - SD-WAN and SASE Solution:

Current Problems:

ProblemCause
Poor cloud performanceAll traffic backhauled through DC
High costsMPLS is expensive
Remote user experienceVPN capacity limits
Security gapsDifferent tools for branch vs remote

Solution Options:

OptionApproach
SD-WAN onlyBetter routing, but security gaps
SD-WAN + securityNeed security at each site
SASENetwork + security converged

SASE Implementation:

SASE Implementation Architecture
Branch Offices
Remote Workers
SASE PoP
Security at PoP:
FWaaSSWGCASBZTNADLP
Cloud Apps
Data Center
Consistent cloud-delivered security for all users • Direct cloud access

Architecture Components:

  • 1.SD-WAN edges at branches
  • 2.SASE agent on user devices
  • 3.Traffic to nearest PoP
  • 4.Security applied in cloud
  • 5.Direct access to SaaS apps
  • 6.Secure tunnel to data center

How SASE Addresses Requirements:

RequirementSASE Solution
Cloud performanceDirect-to-cloud via nearest PoP
Cost reductionReplace expensive MPLS
Remote usersZTNA for app access
Consistent securitySame cloud security for all

Key insight: SASE consolidates SD-WAN routing with cloud-delivered security, providing consistent protection for branch offices and remote users while enabling direct cloud access. This addresses the limitations of traditional hub-and-spoke architectures.

Key Terms

SD-WANSASEsoftware-defined WANSecure Access Service Edgecloud securityZTNAdistributed network security

Common Mistakes

Thinking SD-WAN replaces security—SD-WAN provides basic security but needs additional controls for enterprise protection.
SASE is just cloud VPN—SASE is a comprehensive architecture including FWaaS, SWG, CASB, ZTNA, and more.
ZTNA provides network access—ZTNA provides application-level access only, not full network access like VPN.
SD-WAN only uses internet—SD-WAN can use MPLS, broadband, LTE, and other transports together.

Exam Tips

SD-WAN = software-defined routing + multiple transport options + direct cloud access. Reduces MPLS dependency.
SASE = SD-WAN + cloud-delivered security (FWaaS, SWG, CASB, ZTNA). Everything from the cloud.
ZTNA vs VPN: VPN = network access. ZTNA = application-specific access only. ZTNA is zero trust.
If a question mentions "direct cloud access" or "reducing backhaul," think SD-WAN.
If a question mentions "consistent security for branches and remote users," think SASE.
CASB = Cloud Access Security Broker. Controls access to cloud applications.

Memory Trick

SD-WAN Memory: "Smart Directions for WAN" Intelligent routing, multiple paths, direct to cloud

Traditional vs SD-WAN: "Traditional: All roads lead to Rome (data center)" "SD-WAN: Take the best road to your destination"

  • SASE Components - "FSCZ":
  • Firewall as a Service (FWaaS)
  • Secure Web Gateway (SWG)
  • CASB (Cloud Access Security Broker)
  • ZTNA (Zero Trust Network Access)

SASE Memory: "Security And SD-WAN Everywhere" All security + networking from cloud

ZTNA vs VPN: "VPN = Visitor to the Network (full access)" "ZTNA = Zero Trust, Not All access" Only the specific app, never the network

Why SASE: "Security follows users, not the other way around" Cloud-delivered = protection everywhere

Test Your Knowledge

Q1.A company wants to reduce WAN costs while improving access to cloud applications. What technology should they consider?

Q2.Which SASE component provides application-specific access based on user identity instead of full network access?

Q3.What is the PRIMARY benefit of SASE architecture for organizations with remote workers?

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