Understanding the SDN Switches

17 FEBRUARY 2019

Many of you would have heard the word SDN (software defined networking) but not know what actually it is. Software defined networking is the latest advancement in networking that optimizes the functioning of a network and considerably improves the efficiency. In SDN, a central control layer regulates the flow of information and associated use of bandwidth and other parameters. The SDN controller acts as the virtual brain of the network, thus allow f swift management of network movement by network administrators.

It can be said that network managers are given more leeway than before to manage the network. Moreover, they also dictate to the underlying systems like switches, routers and other network gear, how the network traffic should be managed. Therefore, network engineers can manage the traffic flow, without manipulating or hunting switches individually.

Open application programmatic interfaces (Open APIs) are termed as a set of protocols and tools that are used to build software applications. They are also utilized in SDN to provide support to all the applications and services that operate over the network. These APIs are termed as Northbound APIs. They innovate and facilitate competent service, orchestration and automation.

The main benefit of adopting a SDN is the fact that both capital and operational expenses reduce significantly. With optimization strategies, functional separation and automation can also be achieved. Moreover, it provides higher reliability in network functioning and programmable switches and interfaces mean that scaling up or scaling down of network operation is easy. This is because the traffic load can be adjusted quickly, vigorously and cost-effectively. Without compromising on functionality or efficiency, SDN forms a bridge between the network intelligence part and the physical hardware part.

Many SDN switches behave like a standard Ethernet switch and flood traffic. It floods out the traffic from all ports of Ethernet frames destined to broadcast, multicast or unknown MAC addresses.

If every Ethernet switch can perform like a traditional firewall in the environment, it would have changed the way security policy is implemented in a networked environment. Had every Ethernet switch was a multi-port firewall, the firewall policies could be implemented throughout the network at every switch port and on every link between switches. The main concept of the feasibility of using an SDN switch as a firewall is that it will maintain the application traffic flow.

At a time when existing loopholes like vendor dependence, complexity and inability to scale up or down quickly in a network technology are leading to a slow growth, SDN seems to be the beacon of hope. With the indication of a new era that is more data driven, cloud-centric and application intensive at every touch point, SDN surely looks out to be the perfect answer to the future progress.