You can create a subnet by using System Manager to provide a logical subdivision of an IP network to pre-allocate the IP addresses. A subnet enables you to create interfaces more easily by specifying a subnet instead of an IP address and network mask values for each new interface.
You must have created the broadcast domain on which the subnet is used.
If you specify a gateway when creating a subnet, a default route to the gateway is added automatically to the SVM when a LIF is created using that subnet.