SDN's Core Strength: Centralized Control and Programmability: The fundamental difference between SDN and traditional networking is the separation of the control plane (responsible for routing decisions) from the data plane (responsible for forwarding traffic). This separation allows for centralized control and programmability of the network.
In the context of Layer 4 firewalls, this means:
→ Traditional Firewalls: Operate based on static configurations defined on each firewall device. Changes require manual intervention on each device.
→ SDN-based Firewalls: Can be dynamically configured and reconfigured by the SDN controller. This allows the firewall rules to adapt to changes in network topology, traffic patterns, or security policies in real-time. For example, if a new virtual machine is spun up, the SDN controller can automatically update the firewall rules to allow or deny traffic to that VM.
A) This is the opposite of the truth. SDN allows for dynamic rule adjustments, while traditional firewalls rely on static rules.
C) Both traditional and SDN-based Layer 4 firewalls primarily operate at the transport layer (TCP/UDP ports). Deep packet inspection is typically a function of Layer 7 (Application Layer) firewalls or intrusion prevention systems (IPS).
D) While centralized management is a common characteristic of SDN, it's not the primary difference in operational capability. The key difference is the dynamic nature of rule enforcement due to the programmable control plane. Traditional firewalls can also be managed centrally using management software, although not with the same level of dynamic integration provided by SDN.