A minimum of 1 gigabit networking is required and will provide throughput up to 120 MB/sec (line speed of 1Gb/E). 10Gb/E offers 750+ MB/sec throughput. To reduce the overhead for intensive storage I/O workloads, it is highly-recommended to configure the VMware hosts running SoftNAS and the heavy I/O workloads with "jumbo frames", MTU 9000. It's usually best to allocate a separate vSwitch for storage with dual physical NICs with their VMkernels configured for MTU 9000 (be sure to configure the physical switch ports for MTU 9000, as well). If possible, isolating storage onto its own VLAN is also a best practice.
If you are using dual switches for redundancy (usually a good idea and best practice for HA configurations), be sure to configure your VMware host vSwitch for Active-Active operation and test switch port failover prior to placing your SoftNAS VM into production (like you would with any other production VMware host).
You should choose static IPv4 addresses for SoftNAS. If you plan to assign storage to a separate VLAN (usually a good idea), ensure the vSwitch and physical switches are properly configured and available for use. For VMware-based storage systems, SoftNAS is typically deployed on an internal, private network. Access to the Internet from SoftNAS is required for certain features to work; e.g., Software Updates (which download updates from the Buurst.com site), NTP time synchronization (which can be used to keep the system clock accurate), etc.
From an administration perspective, you will probably want browser-based access from the internal network only. Optionally, you may wish to use SSH for remote shell access (optional). If you prefer to completely isolate access to SoftNAS from both internal and external users, then access will be restricted to the VMware console only (you can launch a local web browser on the graphical console's desktop). Note that you can add as many network interfaces to the SoftNAS VM as permitted by the VMware environment.
Prior to installation, allocate a static IP address for SoftNAS and be prepared to enter the usual network mask, default gateway and DNS details during network configuration. By default, SoftNAS is configured to initially boot in DHCP mode (but it is recommended to use a fixed, static IP address for production use).
At a minimum, SoftNAS must have at least one NIC assigned for management and storage. It is best practice to provide a separate NICs for management/administration, storage I/O and replication I/O.