Configuring private subnets

Clicking the Add Subnet button on the Configure Subnets screen brings up the Private Subnet configuration dialog. At least one private subnet must be defined to enable devices that are connected to the OnBoard appliance’s private Ethernet ports to communicate over the Internet via the OnBoard appliance’s public IP address. Any number of private subnets may be configured.

The following table defines the information that the administrative user must supply in the fields that define a subnet.

Fields on the Private Subnet Configuration Dialog 

Field	Definition
Private subnet name	Any meaningful name chosen by the administrator.
OnBoard side IP address	Devices use this address when communicating with the OnBoard appliance. The OnBoard appliance uses this address when communicating with devices. This address must be within the private subnet’s IP address range.
Subnet mask	Defines the range of addresses available on the subnet.

The OnBoard appliance derives the range of addresses in the subnet from the OnBoard appliance-side IP address and the subnet mask.The OnBoard appliance uses the specified information to create a route to the subnet in the OnBoard appliance’s routing table.

The example in Figure 6.10 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.

Network-Private Subnets: Add Subnet Dialog

Since the broadcast address in the example is 192.168.0.255 (by convention) and the OnBoard’s address is 192.168.0.254, the administrator can assign an IP address out of the remaining available IP addresses between 192.168.0.1 and 192.168.0.253 when configuring a connected device.

Multiple private subnets may be needed if IP addresses are already assigned to connected devices’ Ethernet ports and if the IP addresses are not in the same range.

To add a private subnet:

1.	Log into the Web Manager as an administrative user.

2.	Click the Wizard button.

3.	Click the Subnets option in the left menu bar.

4.	Click the Add Subnet button.

5.	Enter a meaningful name for the private subnet in the Private subnet name field.

6.	Enter an IP address within the private subnet’s network address range in the Onboard side IP address field.

7.	Enter a netmask for the subnet in the Subnet netmask field.

8.

Click OK.

9.	Click Save and apply changes.

10.	Click the Next button, if desired, to go to the next Wizard step.

To edit a private subnet:

1.	Log into the Web Manager as an administrative user.

2.	Click the Wizard button.

3.	Click the Subnets option in the left menu bar.

4.	Click the Edit button for the entry for the private subnet you want to change.

5.	Accept or change the name of the private subnet in the Private subnet name field.

6.	Accept or change the IP address in the Onboard side IP address field.

7.	Accept or change the netmask for the subnet in the Subnet netmask field.

8.

Click OK.

9.	Click Save and apply changes.

10.	Click Next, if desired, to go to the next Wizard screen.