I ask silly questions sometimes, but I do it for a reason. As a teacher, I i try to inspire you to think. So I ask questions that may seem a little goofy, but I also try to gently guide you down a new path.
I’ve been using this for a while in my vSphere classes (everything I teach that discusses networking, at least) and thought it was worth sharing. I lead off the discussion with a simple question: do you treat an ESXi host any differently than any other physical server while planning to attach it to the network? Sure, an ESXi host likely has more interfaces to cable, but that’s not all you need to think about. A fundamental shift in thought process should occur when thinking about your vSphere hosts and your network.
If you look at the vSphere network architecture long enough, it’s clear that you’re not just connecting a host to your network. You’re actually connecting more infrastructure to your network. You’re connecting physical switches to virtual switches, not connecting hosts to physical switches. Your vmnic devices aren’t really NICs at all – they’re bridging physical Ethernet to virtual Ethernet. Once that realization is made, everything’s different.
I’ll admit, I didn’t come to this realization all on my own – a friend of mine actually introduced me to the idea. We were discussing something about a class, and he drew on the whiteboard something that could easily be described as a cabinet in the context of a physical data center, and then began to explain that it could just as easily represent an ESX host (this was a couple of years ago). And the epiphany struck.
It’s easy for us systems guys (and gals) to avoid this thought process. We were never programmed that way. But the times, they are a changin’, and we need to remember to change with them.
If you think about your networking like any old host, let me suggest, kindly, that you’re doing it wrong. Start thinking about adding a cabinet to your raised floor, and then you’ll be right on track.