prospero63 wrote:
The actual objective here is to try to figure out which vmkernel NFS traffic can, and cannot communicate over so I'm open to other ideas and options in pursuit of that goal.
You might try the nc command against port 2049 and specify different outgoing adapters to verify which paths works and which don't:
http://rickardnobel.se/troubleshoot-iscsi-tcp-connectivity-from-esxi-with-netcat