The DHCP First option of the Network Configuration

Configure->NetworkConfig->DHCP-First

When the Server uses DHCP to give out IP addresses to PC's or other devices on the LAN, it must give a different address to each of them. It must therefore be assigned a range of IP addresses to give out. This item is the first IP Address in the range it is allowed to give out.

The range of IP Addresses must be a single contiguous block of addresses avoiding any pre assigned addresses used by other network devices, especially other servers, and must be in the range of addresses defined by the Netmask.

The default values for this field is "10.10.10.2".