Other than that one guideline, best-practice recommendations on the forum vary widely.

I find it's also effective to provide a separate virtual switch for the physical switch linking the physical server to storage. That keeps VMs from fighting for the same bandwidth for access to both network and storage resources.

The common wisdom on security is that VLANs on a vSwitch are currently secure—in some cases more secure than many physical switches—but this may not always be the case.

Splitting traffic amongst the available physical NICs give the best redundancy, performance, and security overall, but how to accomplish this split is far from clear.

Virtualization expert Edward L. Haletky is the author of "VMWare ESX Server in the Enterprise: Planning and Securing Virtualization Servers," Pearson Education (2008.) He recently left Hewlett-Packard, where he worked in the Virtualization, Linux, and High-Performance Technical Computing teams. Haletky owns AstroArch Consulting, providing virtualization, security, and network consulting and development. Haletky is also a champion and moderator for the VMware discussion forums, providing answers to security and configuration questions.