LoadMaster connects to one or more networks. By default, a single interface (eth0) is used for DNS responses. In this documentation, eth0 is assumed to be used as the sole interface used for DNS responses.

In a one-armed configuration, the DNS responder service can be configured for any subnet. The LoadMaster connects to a Layer 2 network through a single interface, eth0.

If a firewall is already in place performing NAT to a DMZ in a non-routable (RFC1918) IP space (for example, 192.168.x.x or 10.x.x.x), please make sure a 1-to-1 NAT for port 53 UDP/TCP exists to the LoadMaster.

Note: If your LoadMaster version is below 7.2.57, we do not recommend a Layer 3 source IP NAT to the LoadMaster as it will mask source IP visibility during geographical coding operations, all devices before the LoadMaster should be transparent.In 7.2.57, the EDNS Client Subnet (ECS) feature was introduced. For further information, refer to the Global section.

The LoadMaster(s) can be located on the DMZ with no large-scale network changes required. As shown in the diagram above, the default gateway of LoadMaster should point to the firewall.