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Software Defined Networking

I have talked to a lot of system administrators over the last couple of months asking them if SDN was on their radar for next year, and until last week none of them were looking at it. To be honest, I was surprised. SDN has the potential to deliver benefits like we saw with X86 virtualization.

  • Hardware abstraction
  • Centralized control and a standard interface.
  • Multi-tenancy for Hybrid cloud, remote office, mergers and acquisitions.
  • Automation, where networks can be configured and managed in an on-demand, self-healing fashion.

Now part of me can understand this. You may think that you are a server admin and networking really isn’t your job, or if you are the person who manages you network infrastructure you might be thinking this is just for the virtualization guys, but understand it has already started to creep into your world. It started with a v-switch, then a distributed v-switch , now nsx and hybrid clouds. I am going to tell you to get on the SDN bus before it leaves the station. There are a lot of companies who have the power to create markets investing Billions in the market, companies like VMware, Cisco, Microsoft and Amazon to name a few. Companies I would not bet against.

Here are a few places where I think companies can start to take advantage of SDN:

Small office with a small IT department, having one interface to manage your virtual infrastructure, storage and now networks would be HUGE. You would not have to learn the ios for your switch manufacturer.

Companies with branch or retail offices: Can you imagine the standardization. No more dreaming up a new IP scheme when you run out of addresses. Now every office, every store has the exact same IP scheme. You would have a addresses for servers, printers, registers.

During mergers and acquisitions: If you have ever been part of merging two networks you know how much work goes into re-assigning IP addresses to every device. With SDN you would not have to do that. You would just put up a gateway and bring them together.

In short, SDN is much like your own personal super highway that is placed on top of the existing infrastructure with on and off ramps only where you need them with one place to manage it all. You should start evaluating what companies are offering and at what price point.

In the very near future years you are going to see a convergence of the server, storage and networking teams. The lines are already beginning to blur in many companies. Not only are you going to be working for the same manager but you are going to be expected to do each other’s jobs, share on call rotations, and pick up each other’s projects. Gone are the days of just being a virtual administrator, windows guy or network administrator. You are going to have to have a better understanding of how your technologies interact or work for someone who does.

2 thoughts on “Software Defined Networking

  1. Peter H


    My experience and continued concern with SDN is the amount of resources ithat must be reserved from you hypervisor servers to manage the SDN. In some cases up to ~50% when considering the HA requirements. This is a hefty cost. Agreed that the benefits of localized storage for active VMs are great including reduced latency and increased redundancy, but when you consider such things as the need for a minimum of three or more servers to run vSAN or one of the many other SDN offerings, you find the value and management considerations weighty especially in a small office setting. Offloading to a single purpose storage appliance still has it’s merits. Offloading the many optimizations such as de-dupe, compression, and snapshots free up you hypervisor’s CPU and RAM to service your customer’s VM’s and not the infrastructure itself.

    Has anyone else felt this way? Am I missing something?

    1. Chris Harney Post author

      Hi Peter,

      Many years ago I blasted my VMware rep for their VDI offering. There were many holes in the product. It was far more expensive than traditional desktops and there were very few management tools. Her response was rather enlightening. What she told me was that they knew they had work to do on the product but until they got it in the hands of users to get real feedback they were only guessing on what features would really be used and which aspects they should work on first.

      With that said, yes I agree that SND is very expensive for most applications. However there are some use cases where it can be leveraged to save time and money. I know of a company on the west coast that has a legacy class A network and they are in a colo. for them to migrate all of their servers to a newer colo is going to take months and lots of resources. they have chosen to implement SDN during their migration so that they can get to the new space with the least amount of disruption and time.

      With respect to vSan, VMware has made this really attractive for VDI customers with the appropriate licenses. However for most other use cases I would probably recommend a lower cost SAN, Stormagic, Simplivity or Nutanix.

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