Nemtallah Daher is Senior Network Delivery Consultant at the consulting firm AdvizeX Technology. Recently he took some time out of his day to talk with us about why, as a networking guy, he thinks learning about network virtualization is critical to further one’s career. 


I’ve been at AdvizeX for about a year now. I do Cisco, HP, data center stuff, and all sorts of general networking things: routing, switching, data center, UCS. That kind of stuff. Before coming to AdvizeX, I was a senior network specialist at Cleveland State University for about 20 years.

I started at Cleveland State in 1988 as a systems programmer, working on IBM mainframe doing CICS, COBOL and assembler. About 2 years after I started at Cleveland State, networking was becoming prevalent, and the project I was working on was coming to an end, so they asked me if I would help start a networking group. So from a small lab here, a building here, a floor there, I built the network at Cleveland State. We applied for a grant to get some hardware, applied for an IP address, domain name, all these things. There was nothing at the time, so we did everything. We incorporated wireless about 10 years in. Over time it became a ubiquitous, campus-wide network. So that’s my brief history.

About a year ago, I decided I needed to challenge myself a little bit more. I had played with VMware a long time before, in the mid-90s. It was cool, but at the time I thought it was more of a toy. You play with these things, but you never think they will really be used in production. Then, about four years ago, I was talking to people in the data center at Cleveland State, and they showed me that they were using VMware in production. I was really kind of shocked. I still had the visions of the toy I had played with 15 years before.

It was the coolest thing. As I started learning more about VMware, about vSphere, I decided, ‘This is really the way to go.’ I took some classes, and I virtualized all the computing platforms for the network department. So really, I became interested in network virtualization because it captured my imagination.

About a year ago, after I got to AdvizeX, my manager called me and said, ‘We have a data program for NSX. Would you be interested?’ I thought, ‘This is going to be a great opportunity for me.’ At some point I had become a little bored with networking; in fact, I felt I needed to revitalize my career.

I’ve always been very interested in VMware; not because it’s my job, but because it’s really something that I enjoy doing. I think the whole technology—virtualization technology—is really cool technology. The first time somebody showed me vMotioning, I was like, ‘Wow, how does this work?’ It seemed like magic. It reminded me of when I first installed wireless at Cleveland State. Same thing. It was like, “wow, this is cool stuff”. So I really wanted an advanced certification in VMware. I wanted to be an expert. I wanted to really be the best in it, if I could be. So, I jumped at the opportunity to get trained, when it was presented. I knew it would open up new opportunities for me that wouldn’t be available if I continued on the networking track I was on.

The initial program was very intense—it lasted four months. I started in March. It was a strict program where you could not procrastinate. You had deadlines, you had specific dates you had to meet. I studied heavily the whole time. I learned a lot. I didn’t know how powerful network virtualization could be. I thought, you build a few switches here and there, and that’s the extent of it. But it is so powerful. It really transforms the data center. You are able to emulate anything that you do in hardware—switches, routers, load balancers, firewalls. There are so many advantages. Network virtualization allows you to build really a very customized, very robust network that would be very costly, and very difficult, to build with hardware. So these are the things that I did not know when I first started.

I learned that virtualization gives you the ability to create and design something on the fly and then implement it quickly, without any long-term process, or hardware acquisition. With virtualization you have the ability to spin up a Windows machine, a Linux machine, any machine, within minutes. It’s an amazing thing for a data center. So if you extend that same concept, from the original virtualization of vSphere, to networking, it becomes so powerful. Imagine a network that’s so flexible and scalable that any changes to it can be accomplished with a few clicks of a mouse. Imagine being able to add routers, switches, firewalls, load balancers, you know, at a moment’s notice. That is what I find so fascinating and so interesting about all this.

If you take the classic data center, what do you have? You’ve got servers, and everything is connected. Routing is done with routers and switches; firewalls are done on hardware, and any time a server administrator needs to make a change they have to get in touch with a network person. Sometimes the hardware is available, sometimes it isn’t. You might need to add a card. You might not have enough ports. Hardware either has to be reconfigured, or some other piece needs to be added to accomplish the task that’s required. Now, with network virtualization, all of that can be done so quickly. If you need a VLAN, you add a VxLAN—a logical switch—to your infrastructure, and that’s just a few mouse clicks. Your underlay configuration doesn’t change; you don’t have to touch the VLAN that you built originally. When everything is done through software, you only have build it correctly, design it correctly, once—and then it’s there for you forever. All the other changes you make are done through software.

Sure, there are people out there right now that say they don’t have to learn about network virtualization, or question the viability of the technology. Those people are probably the same people that didn’t think VMware would take off. They probably didn’t embrace hardware or server virtualization in the past. But, you know, those things are standard now. I think if you’re on board with server virtualization, you won’t be able to help but embrace network virtualization as well. It’s the same principle: you are virtualizing something that was once based in hardware, but that no longer needs to be. If you buy into VMware and virtualization technology at all, you won’t be able to help but believe in network virtualization.

The most common concern you hear from somebody who hasn’t really used or studied network virtualization is about hardware. When you’re running your virtualized network on these Intel boxes that are really not built to be traditional routers or switches, you don’t have specially made hardware and software that is only meant to be switches and routers, as you would in a traditional network infrastructure. But to someone who’s concerned about that, I would say this: these days even network hardware vendors are moving away from specialized hardware. Look at the new Cisco line of switches, the 9300; or at Arista switches and hardware, they are moving away from specialized hardware now, and using off-the-shelf components, trying to reduce the cost of their network infrastructure. Now, if you look at how to design a proper NSX infrastructure, there you have to build redundancy into the hardware as well as the software, in order to mitigate any single point of failure. So even though the network may be built on traditional Intel servers, the design allows you both redundancy and resiliency. So I don’t think that concern is valid. We simply don’t need specialized hardware anymore. If your virtualized network is designed properly, with redundancy, then your network will survive any single point of failure with the same resiliency as any proprietary hardware solution.

These ideas aren’t just theory. In fact, I worked on a project not too long ago at a bank. You might not think banks would be early adopters of emerging technologies, but this bank saw the need to build a structure that it could easily change and adapt. We went ahead and did a very aggressive project in just 2 months, rebuilding this infrastructure for NSX and virtualization—and it was extremely successful. So I think network virtualization will take off very fast. I think within a year or two it’s going to be very prevalent in the industry.

We all need to learn new things, especially things we think are going to be emerging in the near future. If you believe that network virtualization will take off, and will become the way the data center is done in the future, then your choice is either to learn how to do it, or to be left behind. If you don’t invest in educating yourself, you will not be able to converse in this field. You will be left out. We work in a field that changes rapidly. New technologies are emerging on a daily basis. Network virtualization is like anything else: there’ll always be work for traditional engineers, traditional networking. But as a network engineer, if you have ambition, and if you want to embrace change and new technologies, in my opinion network virtualization is something that you must learn.