VMware NSX – What is with the Cisco or NSX debate?

Why is there a perception that you can use Cisco or NSX?  If you perform a simple google search you will find many articles that aim to answer the question of Cisco vs. NSX?  This is like saying HP or vSPhere?  It doesn’t make any sense.  Cisco and NSX can co-exist in a datacenter it’s not a one or the other proposition.  Let’s face it Cisco owns the network layer in most datacenters and they should, they make damn good networking hardware.  But that’s just it.  They make hardware much like HP, Dell, and IBM make hardware.  It has limitations.

Don’t get me wrong hardware is a necessary evil for obvious reasons for all types of  virtualization whether it be computer, networking, or storage.  I just don’t understand the big debate regarding Cisco vs. NSX.  It’s really very simple.  Keep your existing Cisco hardware and get more out of it with NSX.  I hear many making an argument that network virtualization is not needed because you cannot consolidate multiple switches or routers into one.  This baffles me as well.  If you support this argument or feel it is valid you don’t understand the value of Network virtualization

Let’s take a look at some of the benefits of network virtualization:

  1. Automation – Have you ever tried to automate your physical network?  How did that work out for you?  Not well I’m sure.  While some have made it work, it’s not reliable.  With NSX automation of the Networking layer is a reality.  Not just automating simple task such as placement of machines on to networks, but automating security policies, routing, deployment of load balancers, firewalls, VPN servers, and more.  I would love to see this done with physical Cisco hardware.
  2. Traffic off loading – If two virtual machines reside on the same vSphere host, but are on separate physical networks why would you want that traffic to have to leave the vSPhere host and go to the physical network to be routed back to the same physical vSphere server and then to the virtual machine running on the host?  You wouldn’t.  I’m sure Cisco would want you to do that.  They would love for you keep outgrowing the backplane in your switches and routers with unnecessary traffic so you keep upgrading the physical hardware.  Not only can you send traffic from vm to vm on the same host without hitting a physical router you can send traffic from vm to vm across different physical vSPhere hosts without hitting an physical outer to do when those vms reside on different subnets thereby significantly reducing the amount of traffic running through your physical routers.
  3. Network Fencing – With NSX you can deploy network fencing and re-use IP addresses across different fenced environments.  Where this is possible with physical networks why on earth would you want to even try?  You would need to do massive manual configurations of physical routers, switches, and firewall rules as the very least.
  4. Security – NSX provides security that you just couldn’t get from any physical device.  Protection of the VM at the virtual NIC level that follows the VM to whatever host it’s running on.
  5. Micro-Segmentation – This term makes me want to pull a Steve Ballmer and just start repeating myself.  Micro-Segmentation, Micro-Segmentation, Micro-Segmentation,  Micro-Segmentation. Micro-Segmentation, Micro-Segmentation.  I see articles and video’s and all sort of propaganda from Cisco that would lead you to believe micro-segmentation is the only value to NSX.  While Micro-Segmentation adds a huge amount of value, it’s not all the value of NSX.

There are plenty of other benefits to NSX.  The point I’m trying to make is there is no point in comparing Cisco and NSX.  While they are both networking related they are not where near the same.  In fact if we look at Cisco and NSX I would predict that in 10 years Cisco is going to be where x86 hardware is in relationship to vSphere today.  Traditional physical networking, and storage are both heading in the direction of vSphere and VMware is leading the charge.  We all want to get to the Cloud and Software defined data centers are the only way to get there.  Sorry Cisco, but the days of physical networking devices owning the networking stack are over.  Soon all physical networking equipment will simply we a commodity needed to connect the physical wires.

9 Replies to “VMware NSX – What is with the Cisco or NSX debate?”

  1. The primary reason, as I see it, behind the the Cisco vs. NSX debate is that VMware is pitching it like this: by dumping Cisco and putting cheap white box top of rack, NSX will pay for itself.

    1. I wouldn’t agree with that. Although VMware is saying you can run it with any whitebox switch, there is no push to remove Cisco. It’s simply just doesn’t matter what your networking hardware is. There would be no need to remove Cisco and buy something else. You simple leverage whatever you already have Cisco or otherwise. There is no ROI advantage to removing something you already own.

  2. You are asking the wrong question. The question isn´t “Cisco or NSX?”, the question is “NSX or ACI?”. And then the house is usually on FIRE!

    1. That’s the thing I’m not the one asking the questions. Maybe you have a point. Maybe those that are asking the question are leaning towards ACI. I was trying not to go there, but since you already did I might have to put up a blog on it.

    2. I agree, that is the real question. I have been looking for information on NSX vs ACI, but it doesn’t seem like many people are writing about ACI. We got burned early on with the Cisco 1000v, so we have been taking a more cautious approach to Cisco virtual networking.

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