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SonicOS Enhanced 4.0 Administrator Guide
CHAPTER 24
Chapter 24: Using IP Helper

Network > IP Helper

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/us/support/2134_3424.html

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.
Caution 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.