🔹 SDN – Software Defined Networking
🧩 What is Software-Defined Networking (SDN)?
🔹 SDN – Software Defined Networking
It is known in Arabic as "Software-Defined Networking" or "Software-Directed Networking."
It is a modern approach to network management that aims to transfer control from physical devices to software, making network management more flexible and intelligent.
💡 The idea is simple:
In traditional networks:
> Each device (router or switch) must be manually configured, such as setting VLANs, ACLs, or routing.
In SDN:
> You can control the entire network from one location via what is known as a controller,
which is an intelligent program that communicates with devices and automatically distributes settings to them.
⚙ Key Components of SDN
1️⃣ The Control Plane
Contains the controller, which is the central brain of the network and makes traffic, routing, and security decisions.
2️⃣ The Data Plane
Includes the physical devices such as switches and routers, whose task is to execute the controller's commands.
3️⃣ The Application Plane
Includes the programs that interact with the network (such as monitoring or security programs) and communicate with the controller via APIs.
🔄 The relationship between components:
Applications ↔ Controller ↔ Devices
For example:
Applications request the creation of a new VLAN or the activation of QoS.
The controller translates the request and sends it to the devices.
The devices execute the commands without the need to enter manual commands via the CLI.
🌐 The most popular SDN protocols:
▪ OpenFlow – the first and most popular protocol for controlling the controller and switches.
▪ NETCONF / RESTCONF
▪ gRPC / API
🎯 Advantages of software-defined networks:
✅ Centralized network management from a single interface.
✅ Flexibility and speed in changing settings.
✅ Automated operations and reduced human errors.
✅ Better integration with monitoring and security systems.
✅ Significant time and effort savings, especially in data centers and the cloud.
🏢 Examples of popular SDN systems:
▫ Cisco ACI (Application Centric Infrastructure)
▫ VMware NSX
▫ OpenDaylight
▫ Juniper Contrail