You can attach multiple interfaces on the storage system to the same physical network to balance network traffic among different interfaces.
For example, if two Ethernet interfaces on the system named toaster are attached to the same network where four NFS clients reside, specify in /etc/fstab on client1 and client2 that these clients mount from toaster-0:/home. Specify in /etc/fstab on client3 and client4 that these clients mount from toaster-1:/home. This scheme can balance the traffic among interfaces if each of the clients generates about the same amount of traffic.
The storage system always responds to an NFS request by sending its reply on the interface on which the request was received.