Software Defined Networking (SDN)
■ An approach to networking that uses software-based controllers or APIs to communicate with underlying hardware infrastructure and direct traffic on a network
■ A part of Infrastructure as Code (IaC)
● Infrastructure as Code (IaC)
○ Includes provisioning of architectures in which deployment of resources is performed by scripted automation and orchestration
Control Plane
■ Responsible for routing signals to and from a router
■ Makes decisions on traffic prioritization and security
Data Plane
■ Carries user traffic on the network
■ Performs actual switching and routing
Management Plane
■ Administers routers and switches
■ Monitors traffic conditions
■ Manages network configurations
Setting up SDN
■ SDN application is used to define the policy decisions
● Occurs in management plane
● Deployed and operate within control plane
● Traffic is moved by the data plane across the network
Advantages of SDN
■ Flexibility
● SDNs allow mixing and matching of products from different vendors using common API calls
■ Increased Choices
● Provides organizations with increased choices in network development, adding speed and agility to network establishment
■ Automation
● Enables automation of network provisioning
■ Scalability
● Facilitates fully automated deployment of networks
● Critical for high velocity or high availability architectures
■ Security
● Security data is easier to collect, making detection of different traffic patterns in the network unchallenging
Disadvantages
■ Loss of Connectivity
● Loss of connectivity to the SDN controller can lead to network downtime
■ Centralized Controller
● Vulnerable to attacks targeting the singular controller
Types of SDN
■ Open SDN
● Uses open source technologies like OpenFlow, OpFlex, and OpenStack
■ Hybrid SDN
● Combines traditional networking protocols with SDN technologies
■ SDN Overlay
● Creates layers of network abstraction for virtualized network layers on top of physical networks
Security Benefits
■ Logical Isolation
● Provides additional security and logical isolation in the network
■ Zero Trust
● Allows implementing zero-trust security models using SDN overlay
