Network/IP_Helper.htm

The IP Helper allows the SonicWALL security appliance to forward DHCP requests originating from the interfaces on a SonicWALL security appliance to a centralized DHCP server on the behalf of the requesting client. IP Helper is used extensively in routed VLAN environments where a DHCP server is not available for each interface, or where the layer 3 routing mechanism is not capable of acting as a DHCP server itself. The IP Helper also allows NetBIOS broadcasts to be forwarded with DHCP client requests.

For more information on IP Helper, refer to the IP Helper technote at:
http://www.sonicwall.com/support/pdfs/technotes/ip_helper_on_sonicos_enhanced.pdf

IP Helper Settings

Enable IP Helper - enables IP Helper features.

Enable DHCP Support - enables DHCP forwarding from the SonicWALL security appliance to your central DHCP server. If the DHCP server has been enabled, the message "DHCP Server has been enabled. To edit this setting, click here." is displayed. Clicking the link displays the Network > DHCP Server page.

Alert: The SonicWALL DHCP Server feature must be disabled before you can enable DHCP Support on the IP Helper. The Enable DHCP Support checkbox is greyed out until the DHCP Server setting is disabled.

Enable NetBIOS Support - enables NetBIOS broadcast forwarding with the DHCP requests. NetBIOS is required to allow Windows operating systems to browse for resources on a network.

IP Helper Policies

IP Helper Policies allow you to forward DHCP and NetBIOS broadcasts from one interface to another interface.

Adding an IP Helper Policy

Click the Add button under the IP Helper Policies table. The Add IP Helper Policy window is displayed.

The policy is enabled by default. To configure the policy without enabling it, clear the Enabled check box.

Select DHCP or NetBIOS from the Protocol menu.

Select a source Interface or Zone from the From menu.

Select a destination IP address or subnet from the To menu or select Create a new network to create a new Address Object.

Enter an optional comment in the Comment field.

Click OK to add the policy to the IP Helper Policies table.

Editing an IP Helper Policy

Click the Notepad icon in the Configure column of the IP Helper Policies table to display the Edit IP Helper window, which includes the same settings as the Add IP Helper Policy window.

Deleting IP Helper Policies

Click the Delete button to delete all the selected IP Helper policies in the IP Helper Policies table.

Network/IP_Helper.htm