Hi,
My network looks like this

R1,R2,R3 - Devices (similar to routers) with a class C behind them
R4 - Another device, with 4 physical ports, three of them connected to R1,R2,R3
R4's fourth physical port connects to a network with a DHCP server (Win2k) in it.

The goal: PCs behind R1-R3 will issue a DHCP request which will be relayed
by the relevant Rx to the DHCP server.

Problem: How can the DHCP server assign three different scopes ?

Optimally, I would like to tell the server: If the relay is done by R1
use scope1, etc. I couldn't find anything like it.

Any other solution ?
Are there DHCP servers out there that can do the job ?

TIA

If you configure the routers 1, 2, and 3 to relay dhcp requests to the DHCP
server, they will add their address to the GIADDR field of the DHCP packets
so the DHCP server will know which scope to use. You need no extra
configuration on the DHCP server.

--

Thanks,
Marc Reynolds
Microsoft Technical Support

This posting is provided "AS IS" with no warranties, and confers no rights.


"T Shilo" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Hi,
> My network looks like this
>
> R1,R2,R3 - Devices (similar to routers) with a class C behind them
> R4 - Another device, with 4 physical ports, three of them connected to
R1,R2,R3
> R4's fourth physical port connects to a network with a DHCP server (Win2k)
in it.
>
> The goal: PCs behind R1-R3 will issue a DHCP request which will be relayed
> by the relevant Rx to the DHCP server.
>
> Problem: How can the DHCP server assign three different scopes ?
>
> Optimally, I would like to tell the server: If the relay is done by R1
> use scope1, etc. I couldn't find anything like it.
>
> Any other solution ?
> Are there DHCP servers out there that can do the job ?
>
> TIA

So, what you are saying, is that if I configure scopes 1.1.1.0/24 and
2.2.2.0/24 and router A is 1.1.1.1 and B is 2.2.2.1 then the allocations
would be done accordingly ?
How does this "magic" happen ?
Is this some internal logic of the DHCP server ?
Anywhere you can point me in official documenation ?

What happens if A is 3.3.3.1 ? Which address is chosen for the allocation ?


"Marc Reynolds [MSFT]" <(E-Mail Removed)> wrote in message news:<(E-Mail Removed)>...
> If you configure the routers 1, 2, and 3 to relay dhcp requests to the DHCP
> server, they will add their address to the GIADDR field of the DHCP packets
> so the DHCP server will know which scope to use. You need no extra
> configuration on the DHCP server.
>
> --
>
> Thanks,
> Marc Reynolds
> Microsoft Technical Support
>
> This posting is provided "AS IS" with no warranties, and confers no rights.
>
>
> "T Shilo" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
> > Hi,
> > My network looks like this
> >
> > R1,R2,R3 - Devices (similar to routers) with a class C behind them
> > R4 - Another device, with 4 physical ports, three of them connected to
> R1,R2,R3
> > R4's fourth physical port connects to a network with a DHCP server (Win2k)
> in it.
> >
> > The goal: PCs behind R1-R3 will issue a DHCP request which will be relayed
> > by the relevant Rx to the DHCP server.
> >
> > Problem: How can the DHCP server assign three different scopes ?
> >
> > Optimally, I would like to tell the server: If the relay is done by R1
> > use scope1, etc. I couldn't find anything like it.
> >
> > Any other solution ?
> > Are there DHCP servers out there that can do the job ?
> >
> > TIA

Yes.
There's no "magic" it the design of DHCP.
Yes, it is written to work this way
120932 DHCP: Spanning Multiple Subnets
http://support.microsoft.com/?id=120932

If you have a scope for 3.3.3.x an address will be assigned.

Remember you also need to configure routers to do DHCP relay (or Bootp
relay).

--

Thanks,
Marc Reynolds
Microsoft Technical Support

This posting is provided "AS IS" with no warranties, and confers no rights.


"T Shilo" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> So, what you are saying, is that if I configure scopes 1.1.1.0/24 and
> 2.2.2.0/24 and router A is 1.1.1.1 and B is 2.2.2.1 then the allocations
> would be done accordingly ?
> How does this "magic" happen ?
> Is this some internal logic of the DHCP server ?
> Anywhere you can point me in official documenation ?
>
> What happens if A is 3.3.3.1 ? Which address is chosen for the allocation
?
>
>
> "Marc Reynolds [MSFT]" <(E-Mail Removed)> wrote in message
news:<(E-Mail Removed)>...
> > If you configure the routers 1, 2, and 3 to relay dhcp requests to the
DHCP
> > server, they will add their address to the GIADDR field of the DHCP
packets
> > so the DHCP server will know which scope to use. You need no extra
> > configuration on the DHCP server.
> >
> > --
> >
> > Thanks,
> > Marc Reynolds
> > Microsoft Technical Support
> >
> > This posting is provided "AS IS" with no warranties, and confers no
rights.
> >
> >
> > "T Shilo" <(E-Mail Removed)> wrote in message
> > news:(E-Mail Removed)...
> > > Hi,
> > > My network looks like this
> > >
> > > R1,R2,R3 - Devices (similar to routers) with a class C behind them
> > > R4 - Another device, with 4 physical ports, three of them connected to
> > R1,R2,R3
> > > R4's fourth physical port connects to a network with a DHCP server
(Win2k)
> > in it.
> > >
> > > The goal: PCs behind R1-R3 will issue a DHCP request which will be
relayed
> > > by the relevant Rx to the DHCP server.
> > >
> > > Problem: How can the DHCP server assign three different scopes ?
> > >
> > > Optimally, I would like to tell the server: If the relay is done by R1
> > > use scope1, etc. I couldn't find anything like it.
> > >
> > > Any other solution ?
> > > Are there DHCP servers out there that can do the job ?
> > >
> > > TIA

If the routers do not support bootp or relay agents, you can configure RRAS
on a 2K or 2K3 server on each subnet to do this.

"Marc Reynolds [MSFT]" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Yes.
> There's no "magic" it the design of DHCP.
> Yes, it is written to work this way
> 120932 DHCP: Spanning Multiple Subnets
> http://support.microsoft.com/?id=120932
>
> If you have a scope for 3.3.3.x an address will be assigned.
>
> Remember you also need to configure routers to do DHCP relay (or Bootp
> relay).
>
> --
>
> Thanks,
> Marc Reynolds
> Microsoft Technical Support
>
> This posting is provided "AS IS" with no warranties, and confers no
rights.
>
>
> "T Shilo" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
> > So, what you are saying, is that if I configure scopes 1.1.1.0/24 and
> > 2.2.2.0/24 and router A is 1.1.1.1 and B is 2.2.2.1 then the allocations
> > would be done accordingly ?
> > How does this "magic" happen ?
> > Is this some internal logic of the DHCP server ?
> > Anywhere you can point me in official documenation ?
> >
> > What happens if A is 3.3.3.1 ? Which address is chosen for the
allocation
> ?
> >
> >
> > "Marc Reynolds [MSFT]" <(E-Mail Removed)> wrote in message
> news:<(E-Mail Removed)>...
> > > If you configure the routers 1, 2, and 3 to relay dhcp requests to the
> DHCP
> > > server, they will add their address to the GIADDR field of the DHCP
> packets
> > > so the DHCP server will know which scope to use. You need no extra
> > > configuration on the DHCP server.
> > >
> > > --
> > >
> > > Thanks,
> > > Marc Reynolds
> > > Microsoft Technical Support
> > >
> > > This posting is provided "AS IS" with no warranties, and confers no
> rights.
> > >
> > >
> > > "T Shilo" <(E-Mail Removed)> wrote in message
> > > news:(E-Mail Removed)...
> > > > Hi,
> > > > My network looks like this
> > > >
> > > > R1,R2,R3 - Devices (similar to routers) with a class C behind them
> > > > R4 - Another device, with 4 physical ports, three of them connected
to
> > > R1,R2,R3
> > > > R4's fourth physical port connects to a network with a DHCP server
> (Win2k)
> > > in it.
> > > >
> > > > The goal: PCs behind R1-R3 will issue a DHCP request which will be
> relayed
> > > > by the relevant Rx to the DHCP server.
> > > >
> > > > Problem: How can the DHCP server assign three different scopes ?
> > > >
> > > > Optimally, I would like to tell the server: If the relay is done by
R1
> > > > use scope1, etc. I couldn't find anything like it.
> > > >
> > > > Any other solution ?
> > > > Are there DHCP servers out there that can do the job ?
> > > >
> > > > TIA
>
>

Hello All,

Yes you can have a RRAS server as a DHCP relay agent.

232703 How to Use DHCP to Provide Routing and Remote Access Clients with
http://support.microsoft.com/?id=232703



Shane Brasher
MCSE (2003,2000,NT),MCSA Security, N+, A+
Microsoft Platforms Support
Windows NT/2000 Networking