Service Pack 4 Dynamic Host Configuration Protocol (DHCP) Server

• Microsoft Windows NT Workstation version 4.0 SP4
• Microsoft Windows NT Server version 4.0 SP4
• Microsoft Windows NT Server, Enterprise Edition version 4.0 SP4

IMPORTANT: This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore it if a problem occurs. For information about how to do this, view the "Restoring the Registry" Help topic in Regedit.exe or the "Restoring a Registry Key" Help topic in Regedt32.exe.

SUMMARY

The version of the Microsoft Dynamic Host Configuration Protocol (DHCP) Server that ships with Windows NT 4.0 Service Pack 4 modifies the format of the DHCP database. You should back up the contents of your %windir%\system32\dhcp folder prior to upgrading.

The address conflict detection feature can limit the throughput of Microsoft DHCP Server. For improved performance, reduce the number of ping retries in the Server Properties dialog box. This feature is disabled by default.

Address conflicts are indicated by the replacement of the machine name with "BAD_ADDRESS." If a Unique Identifier is specified for the address in the Client Properties dialog box, then the address was declined by the client. If the Unique Identifier is not specified, then the address conflict was detected by the DHCP Server.

MORE INFORMATION

Microsoft DHCP Server can be configured to set a client's default gateway equal to its IP address. This causes the client to use the Address Resolution Protocol (ARP) for all IP addresses on the local subnet and is useful for routerless networks. To enable this feature for all clients in a scope, add the following value to the registry:

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys And Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it.

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\ DHCPServer\configuration\Subnets\a.b.c.d

The above registry is one path: it has been wrapped for readability.

The a.b.c.d is the network ID for the scope you want to change. add value ---SwitchedNetworkFlag (REG_DWORD) Value is = 1 hex

This version of Microsoft DHCP Server supports BOOTP clients. BOOTP addresses currently must be reserved in advance by creating an IP address reservation. Future versions of Microsoft DHCP Server will be capable of leasing dynamic addresses to BOOTP clients.

BOOTP clients that do not specify the parameter request list option (55) can still retrieve the following options from this release of Microsoft DHCP Server:

+-------------------------------------------------------+

| 1  | Subnet Mask                                      | 

| 3  | Router                                           | 

| 5  | Name Server                                      | 

| 12 | Host Name                                        | 

| 15 | Domain Name                                      | 

| 44 | NetBIOS over TCP/IP Name Server                  | 

| 46 | NetBIOS over TCP/IP Node Type                    | 

| 47 | NetBIOS over TCP/IP Scope                        | 

| 48 | X Window System Font Server                      | 

| 49 | X Window System Display Manager                  | 

| 69 | SMTP Server                                      | 

| 70 | POP3 Server                                      | 

| 9  | LPR Server                                       | 

| 17 | Root Path                                        | 

| 42 | NTP Servers                                      | 

| 4  | Time Server                                      | 

In order to obtain other options, the client must specify option 55 in the BOOTP request. DHCP Server will return the options in the order listed above. DHCP Server will return as many options as will fit in response packet.

The activity log feature creates a text log file of all DHCP Server activity. The file is located at:

   %windir%\system32\dhcp\dhcpsrv.log

net stop dhcpserver

If available disk space becomes low, the activity log will pause until sufficient disk space becomes available.

You must also stop and restart the DHCP Server after enabling or disabling Logging, Superscope, or DHCP Decline support.