I was asked a question on LinkedIn about the different virtualization networking strategies from a host point of view. The question came from someone who recently had 10GbE infrastructure introduced in to his data center and the way the network originally was architected was with 6 x 1 Gbps carved up in three bundles of 2 x 1Gbps. Three types of traffic use their own pair of NICs: Management, vMotion and VM. 10GbE was added to the current infrastructure and the question which came up was: should I use 10GbE while keeping my 1Gbps links for things like management for instance? The classic model has a nice separation of network traffic right?
Well I guess from a visual point of view the classic model is nice as it provides a lot of clarity around which type of traffic uses which NIC and which physical switch port. However in the end you typically still end up leveraging VLANs and on top of the physical separation you also provide a logical separation. This logical separation is the most important part if you ask me. Especially when you leverages Distributed Switches and Network IO Control you can create a great simple architecture which is fairly easy to maintain and implement both from a physical and virtual point of view, yes from a visual perspective it may be bit more complex but I think the flexibility and simplicity that you get in return definitely outweighs that. I definitely would recommend, in almost all cases, to keep it simple. Converge physically, separate logically.