DHCP Server Service wont start

[Paul Landregan]

We have an established enterprise forest containing many domains. Each
domain is on a separate subnet, connected together via routers into a
central management domain/subnet.
eg. server1.class1.domain.com server1.class2.domain.com etc etc.

Each classroom is on a separate subnet 172.20.x.0 /24, with a single IP
uplinking to higher formations of 172.20.1.x (Where x is the same in both
addresses).
Each classroom has its own DHCP server serving the clients on that subnet.
This works perfectly. We now wish to add in 6 more classrooms in the same
fashion, however instead of being part of the AD forest, they are required
to be in a workgroups.

All went fine till we tried to configure the DHCP server to issue out
addresses. It recognises there is a DHCP serving the higher formation
172.20.1.100-199 above the fixed uplink IP's. So will not start. The error
ID is 1052.

What could be causing this?
Is it the fact the DHCP server in the root subnet/domain is authorised as
are all the existing classrooms, but the new ones are not authorised, as the
server is part of a workgroup not the existing forest.

How can I get the new DHCP servers to start and issue addresses to their
respective classes.

 

[Doug Sherman [MVP]]

If a workgroup DHCP detects a domain DHCP server on the network, the
workgroup server assumes itself to be unauthorized and will not service DHCP
requests - See:

http://download.microsoft.com/download/4/3/6/436b493e-6d2c-4002-9d86-b45a627925a4/dhcp.doc

Try editing the registry;

Set the following registry key:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\DHCPServer\Parameters

Value name: DisableRogueDetection

Data type: REG_DWORD Value data: 1

Doug Sherman

MCSE Win2k/NT4.0, MCSA, MCP+I, MVP

 

[Paul Landregan]

Yes that's whets happening. Is there a way to add in the workgroup servers
into the authorised list in AD. To allow them to operate.

 

[Paul Landregan]

You stated in a workgroup... here you go:
http://support.microsoft.com/default.aspx?scid=kb;en-us;323416

It says if a server deems itself to be unauthorised it will not service
clients.
So how can I authorise workgroup DHCP servers, in a forest environment.
These classrooms have to remain workgroups, as it is part of the scenario.
The software in these rooms is designed for a workgroup environment,. Where
as the rest of the school classrooms are in domains.

 

[Paul Landregan]

Try editing the registry;

Set the following registry key:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\DHCPServer\Parameters

Value name: DisableRogueDetection

Data type: REG_DWORD Value data: 1

Doug Sherman

MCSE Win2k/NT4.0, MCSA, MCP+I, MVP

Forgot to mention your registry key. I will give that a try on the 6
workgroup DHCP servers. I have been reading up on this, and indeed thsi
seems the only option. Even adding the IP addresses manually into the
authorised list would not work as the workgroup server could not connect
with AD.

 

[Paul Landregan]

If a workgroup DHCP detects a domain DHCP server on the network, the
workgroup server assumes itself to be unauthorized and will not service
DHCP
requests - See:

http://download.microsoft.com/download/4/3/6/436b493e-6d2c-4002-9d86-b45a627925a4/dhcp.doc

Try editing the registry;

Set the following registry key:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\DHCPServer\Parameters

Value name: DisableRogueDetection

Data type: REG_DWORD Value data: 1

Doug Sherman

MCSE Win2k/NT4.0, MCSA, MCP+I, MVP

Many thanks Doug. That key did exactly what it says it does. DHCP server
runs perfectly.

 

[Doug Sherman [MVP]]

Glad it worked - I love feedback.

doug Sherman
MCSE Win2k/nT4.0, MCSA, MCP+I, MVP