CautionHKLM\SYSTEM\CurrentControlSet\Services\DhcpServer\Parameters
| Data type | Range | Default value |
|---|---|---|
| REG_DWORD | 0 | 1 | 1 |
Determines whether the DHCP server complies with or ignores the value of the broadcast bit (broadcast flag) in a client DHCP Discover message.
By default, Windows 2000 DHCP servers ignore the broadcast bit on the client requests. Instead, they send all DHCP responses as IP broadcasts to the limited broadcast address (255.255.255.255). However, a DHCP server can be configured to unicast responses if the client request specifies that a broadcast response is not required.
On Microsoft DHCP clients, the broadcast bit is not set, that is, it is set to request initial Dhcpoffer and Dhcpack packets in unicast messages.
| Value | Meaning |
| 0 | Comply with broadcast flag in client request. |
| 1 | Ignore the broadcast flag in client requests and broadcast all DHCP packets |
You must restart the system before a change to this value takes effect.
Caution
Setting IgnoreBroadcastFlag to 0 reduces broadcast traffic. However, clients cannot receive unicast Dhcpoffer and Dhcpack packets unless the Microsoft DHCP server and DHCP client are on a homogeneous Ethernet network or the same subnet of a Token Ring network. Do not change the default broadcast behavior of a Microsoft DHCP server if the server and client are on different Token Ring subnets or are separated by a router or bridge that does MAC level address translation, for example, Ethernet to or from Token Ring.