Role of Physical networks and SDN/Virtual networks — Network world is evolving

Physical network will only carry the packets. [Routers]

The Software defined networking — Overlay network will provide the Networking Services [Switch, Routing, Load balancer, Firewall, Security] as Software API/Controls.

SDN makes Physical network management operations:

• easy to manage
• easy to scale and change
• provisioning and automation of Networking services
• use any Hardware devices from any Company
• no Vendor lock-in for Networking hardware devices
• app migration from One Datacenter to another Datacenter is simple
• the firewalls/Security policies move along with the Application/VM
• to create Micro-segmentation - create virtual networks and Subnets using simple UI or API calls. Do not touch the network Devices & Configuration
• manage Security easily

VM has an MAC address — layer2 address. If you want to move the VM from one Network to another Network, we have to make many changes to our Network as the VM attributes will change accordingly.

Security in Traditional network world, is based on Machine: ID/IP/Name. The Firewall rules are based on Machine Identifiers. But what if there are more than 100 to 1000 Apps or Containers or Microservices running on a Single machine. What about the virtual networks and subnets within the same Machine?

But in the Futuristic networking world, Firewall rules/Security Policies will be tied to the Application and not to Machines. This gives a Granular control at the App level and also minimizes the attack perimeter.

Also when the App moves from Machine to Machine or from Datacenter to any other Datacenter or Cloud provider, the objects, configuration and settings will also move along with the App/Microservice.