VMware Distributed switches or stick with Standard switches?
Distributed switches have been around for a couple of years now. I run into them at about half the clients I work with. For context, at least half my accounts are in the SMB range so this could account for the splits in configurations.
There are definitely a few advantages to Distributed switches (vDS). The first and easiest to apply is standardization for all the VLAN Port groups you have to create for your vSphere hosts. If you are in an environment with dozens and dozens of VLANs (not necessarily Hosts), creating them once in a vDS will save you a lot of time and be free of mistypes and mistakes. For me, this is one of the first points I look at for whether to roll out Distributed Switches. The number of ESXi hosts matter less to me than the number of VLANs across them. The time saved creating the VLANs once in the vDS will be more beneficial than any perceived complications to the environment by abstracting the networks from the hosts.
That said, what if you have a lot of hosts and just a few VLANs to create? Standard switches might fit the bill just fine. Off the bat, with that decision, you are giving up the ability to have Network vMotion and Inbound traffic shaping. Those two features are only available in Distributed Switches. If there is a security team and they are interested in deploying Port Mirroring; vDS is the only option for that. There is also NetFlow, Load based Teaming and some other ‘niche’ features that are only available in the Distributed Switch.
But if none of these situations apply to your environment, you might not need Distributed Switches. pause & review
As I am writing out these thoughts and reading them back, I am leaning more and more toward Distributed Switches in all but the smallest environments. 😉 Originally, when I had sat down to write my ideas out for the blog, it was after having an experience with a client running Distributed Switches and having physical NIC/Port issues. Since the Distributed Switches were defined in the vCenter, from the ILO console screen, we no longer had access to the physical NIC settings in the DCUI. This presented a variety of challenges in troubleshooting with the networking team and made me start thinking about whether vDS was worth it in this situation. The client only had a few VLANs which could easily be created via PowerShell across a ton of hosts with consistency and didn’t really need all of the other features in the vDS.
I really thought in the beginning of this blog post, I would be lobbying for Standard Switches throughout but now as I come to the end of it, I think I was letting this edge case affect my overall decision for future recommendations. Most clients (hopefully) won’t have these types of issues and the consistency of the Distributed Switch is probably something that will impact the day to day operations of the environment far more than any implementation hurdles over the long haul. It would make more sense to recommend the vDS from the start and set the client up with the right framework for growth.
I think that is where my head is at now. I’m curious what your thoughts are. Do you prefer VMware Standard or Distributed Switches?
Happy Networking!