The administrator must define at least one subnet to enable devices that are connected to the OnBoard’s private Ethernet ports to communicate on the Internet via the OnBoard’s public IP address. Any number of private subnets may be configured.Note: The OnBoard attempts to reach a device that does not have a private subnet assigned by attempting to contact it through the OnBoard’s default route. Therefore, unless the OnBoard administrator defines a public subnet and assigns it to each device, the device cannot be reached unless the device is on the public side of the OnBoard. In almost all cases, devices are on the private side of the OnBoard and therefore they are unreachable without a private subnet.When an administrative user clicks the “Add Subnet” button on the Network Æ Private Subnets Screen, the “Private Subnet configuration” dialog appears, as shown in the following screen example.Network Æ Private Subnets: Add Subnet Dialog
OnBoard side IP address Devices use this address when communicating with the OnBoard. The OnBoard uses this address when communicating with devices. This address must be within the private subnet’s IP address range) The OnBoard derives the range of addresses in the subnet from the OnBoard-side IP address and the subnet mask. The OnBoard uses the specified information to create a route to the subnet in the OnBoard’s routing table.The example in Network Æ Private Subnets: Add Subnet Dialog shows a private subnet name of “net1,” an OnBoard side IP address of 192.168.0.254, and a subnet netmask of 255.255.255.0.Network Æ Private Subnets: Add Subnet DialogThe example in Network Æ Private Subnets: Add Subnet Dialog shows a private subnet name of “net1,” an OnBoard side IP address of 192.168.0.254, and a subnet netmask of 255.255.255.0. The private subnet address derived from this configuration is 192.168.0.0. Since the broadcast address is 192.168.0.255 (by convention) and the OnBoard’s address is 192.168.0.254, the administrator can assign an address between 192.168.0.1 and 192.168.0.253 when configuring a connected device.