IgnoreBroadcastFlag

HKLM\SYSTEM\CurrentControlSet\Services\DhcpServer\Parameters

Data type

Range

Default value

REG_DWORD

0 | 1

1

Description

Determines whether the Dynamic Host Configuration Protocol (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 broadcast flag in client requests, and broadcast all DHCP packets

Activation method

You must restart the system before a change to this value takes effect.

Note Image Note

Windows 2000 does not add this entry to the registry. You can add it by editing the registry or by using a program that edits the registry.

Caution Image Caution

Setting the value of this entry 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.