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It has been 10 years since we understood that voice and video networks would converge with our data networks. It has been no less than six years since we came to accept the dissolution of the traditional perimeter of the enterprise network, at least in terms of our security thinking. In the last five years or so, we've come to accept the convergence of storage and data networks in the data center. Now we are layering on virtual networks, mobile devices and cloud services, and anticipate a software-defined networking (SDN) world. Our management and monitoring tools need to keep up if we are going to keep our networks up.
Uncertainty about network visibility
The unifying theme underlying many of the changes facing the network is a loss of certainty as to where and how many entities are connected to the network. This is true for virtual networks, cloud networks and, most of all, for accommodating the rapid rise of mobile devices in the enterprise. It affects both the back-end systems providing services and the user-facing devices consuming them, and so affects everything from managing a service-level agreement to ensuring solid application performance.
Virtual networks in or among data centers overlay physical networks and create a topology separate from that of the physical network, one upon which virtual machines are added and removed and moved dynamically. To that end, management tools must map the overlaid networks (there can be many) and monitor performance on them, as well as keep tabs on any underlying physical switches and routers that support the virtual networks. These tools will ideally be able to track virtual machines from creation through any movements and to retirement or hibernation (and be able to cope with a machine reappearing after an absence).
Cloud networks serve externally sourced resources, such as application stacks running on infrastructure as a service resource pools from providers like Amazon or Google. They also link internally sourced services to those external resources. Cloud resources create externally hosted virtual networks, and thus pose the same challenges regarding the ability to pinpoint the number and locations of endpoints. What's more, they are opaque at the underlay: You can't monitor physical switch health. This only increases the importance of visibility into the behaviors of the virtual networks. And, of course, the number of different opaque physical infrastructures on which those virtual overlays are built is itself variable. An enterprise may rapidly change cloud service providers, or add to or remove from a pool of them.
Perhaps what is most dynamic and challenging is coping with the influx of mobile devices on enterprise WLANs. While we see a steady and rapid increase in the number over time -- and can safely expect that increase to continue for some years to come -- the number of mobile devices connected at any given moment fluctuates wildly. Moreover, as staff or customers move through a facility, the physical network components through which traffic hits the enterprise network can vary quickly as well. The location of a "top talker" or "top listener" on the network can vary second by second -- even if the node in question is the same! So management tools need to get better at tracking transient connections, both in the sense of devices appearing and disappearing and in the sense of them moving from place to place on the physical network. Management platforms also need to become more proficient in how they exploit network access control or mobile device management data to attach permanent identities to nodes that come and go (to better monitor user or device behavior over time).
Looking ahead a few years, management tools will need to take into account yet another layer of dynamism, as SDN begins to transform how we look at providing connectivity. One key underlying assumption in SDN: Any data plane device can implement any number of services, including providing deep visibility into network traffic and behavior. Management tools will have a new cornucopia of data to work with -- but a completely dynamic and fluid environment to understand and to make comprehensible and manageable to IT staff.
Retooling network management
Enterprise management tools have to mirror enterprise business and operational aspirations. The new enterprise network has to power an enterprise that wants to be agile with virtualization, cloud and mobility. In order for IT to provide services effectively in this evolving environment, management and monitoring tools have to support these business goals by ensuring an IT infrastructure capable of accommodating the dynamism of virtual, cloud, mobile and -- someday -- software-defined networks.
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