DHCP Client registration problems

I have several clients that are not picking up a lease from the DHCP server.
All the clients are XP, some SP1, some SP2.

Each client will request an address and the DHCP server will give it the
lease. Then the client repeatedly requests the same address and the server
responds with NACKs.

The only workaround I've found is to reserve address for the clients
affected and give them static addresses.

Any ideas what the problem is?

Duane Walker

Are you using Multiple DHCP servers for fault tolerance with Superscopes?

If so this might be the problem and the solution

Configuring Multiple DHCP Servers for the Same Superscope
When more than one DHCP server is used to service a superscoped segment, the
superscope for each DHCP server should be configured to include all subnets,
using placeholder values for subnets it does not supply addresses to, but
must recognize as valid.

For example, consider a segment running four logical IP subnets
(192.168.1.0, 192.168.2.0, 192.168.3.0, and 192.168.4.0, all with mask
255.255.255.0). This segment is supported by two DHCP servers, each
configured with a superscope covering half of the subnets (SRV1's superscope
contains only subnets 192.168.1.0 and 192.168.2.0, and SRV2's superscope
contains only subnets 192.168.3.0, 192.168.4.0). As DHCP requests come in
from clients, addresses can be assigned from either of the servers' scopes.
However, a problem can arise if a client is given an IP address from SRV1,
and then its renewal request is received by SRV2. SRV2 does not recognize
the client's address as belonging to that subnet and responds to the client
by sending a DHCP NACK.

This problem is easily avoided by configuring both SRV1 and SRV2 with all
logical IP subnets and using exclusions to prevent the servers from
overlapping address ranges. SRV1 should have a superscope containing all
four subnets and exclude all the addresses of the last two subnets, and SRV2
should also have a superscope containing all four subnets and exclude all
the addresses of the first two subnets.""




"Duane Walker" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
>I have several clients that are not picking up a lease from the DHCP
>server. All the clients are XP, some SP1, some SP2.
>
> Each client will request an address and the DHCP server will give it the
> lease. Then the client repeatedly requests the same address and the
> server responds with NACKs.
>
> The only workaround I've found is to reserve address for the clients
> affected and give them static addresses.
>
> Any ideas what the problem is?
>
> Duane Walker
>

We only run a single DHCP server. It resides on a separate VLan from the
clients but a helper address has been configured so that the DHCP requests
are forwarded.

This all started happening after a domain migration (2000 to 2003, new
forest and domain). I'm sure how that could be connected though.

Thanks,

Duane

"Steve Bruce, mct" <(E-Mail Removed)> wrote in message
news:%(E-Mail Removed)...
> Are you using Multiple DHCP servers for fault tolerance with Superscopes?
>
> If so this might be the problem and the solution
>
> Configuring Multiple DHCP Servers for the Same Superscope
> When more than one DHCP server is used to service a superscoped segment,
> the superscope for each DHCP server should be configured to include all
> subnets, using placeholder values for subnets it does not supply addresses
> to, but must recognize as valid.
>
> For example, consider a segment running four logical IP subnets
> (192.168.1.0, 192.168.2.0, 192.168.3.0, and 192.168.4.0, all with mask
> 255.255.255.0). This segment is supported by two DHCP servers, each
> configured with a superscope covering half of the subnets (SRV1's
> superscope contains only subnets 192.168.1.0 and 192.168.2.0, and SRV2's
> superscope contains only subnets 192.168.3.0, 192.168.4.0). As DHCP
> requests come in from clients, addresses can be assigned from either of
> the servers' scopes. However, a problem can arise if a client is given an
> IP address from SRV1, and then its renewal request is received by SRV2.
> SRV2 does not recognize the client's address as belonging to that subnet
> and responds to the client by sending a DHCP NACK.
>
> This problem is easily avoided by configuring both SRV1 and SRV2 with all
> logical IP subnets and using exclusions to prevent the servers from
> overlapping address ranges. SRV1 should have a superscope containing all
> four subnets and exclude all the addresses of the last two subnets, and
> SRV2 should also have a superscope containing all four subnets and exclude
> all the addresses of the first two subnets.""
>
>
>
>
> "Duane Walker" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
>>I have several clients that are not picking up a lease from the DHCP
>>server. All the clients are XP, some SP1, some SP2.
>>
>> Each client will request an address and the DHCP server will give it the
>> lease. Then the client repeatedly requests the same address and the
>> server responds with NACKs.
>>
>> The only workaround I've found is to reserve address for the clients
>> affected and give them static addresses.
>>
>> Any ideas what the problem is?
>>
>> Duane Walker
>>
>
>