windows 2003 dhcp over 2 subnets

Either the router connecting the subnets needs to support RFC 1542 (BootP relay-agent) or you can install a relay agent on one of the Windows servers/clients already on the DHCP server's subnet (I don't like this option much since the second subnet relies heavily on a computer that's more likely to be rebooted according to its own schedule without regard for the impact).  In addition, you could of course connect the DHCP server to both segments by adding a second NIC.

Regardless, the DHCP server will select an address from the correct scope (assuming you've created two scopes suitable for the two subnets) because the router/relay-agent will modify the lease request to allow the DHCP server servicing it to determine which scope to pull the address out of.

thanks for this, so ok i create my main scope x.x.x.x mask 255.0.0.0, i then tried to create my second scope under superscope x.x.x.x mask 255.255.255.0 it stops with an error after i clcik finsih "subnet address and mask is inconsistent with existing one"

cheers

Can you supply the actual scope values, I can't determine the cause without the numbering scheme you're using?  I can, of course, guess but the numbers would help no end.

sorry subnet1 is 10.0.0.0 255.0.0.0 and subnet2 is 10.10.1.0 mask 255.255.255.0

cheers

In addition, and not wishing to argue but you really do not need to use superscopes.  You simply need two scopes suitably configured for the subnets in question.

if i configure two scopes how do i configure it so that only pc's on subnet 1 get subnet 1 scope and subnet 2 pcs only get subnet 2 scope addresses

As you've defined it, subnet1 consumes subnet2 ... thus the error.  Any computer on subnet1 will deem all computers on subnet2 local and refuse to use the router.  This cannot be working as is.  Are these really the subnets in play right now or your interpretation of using superscopes to solve the problem?

these subnet were never physically connected but they are being physically connected now

cheers

>> these subnet were never physically connected but they are being physically connected now

Ah, :0(  ... then we seem to have a problem.  Are you in a position to alter the entire subnetting scheme for one or both of these subnets?

yes i dont see this as a problem as long as both subnets can still talk to one another

How many devices (clients, servers, printers, etc.) per subnet?

i can redo subet 2 but not 1 and 2 has about 30 ip addresses in use

That's not a major problem but it does mean we need to alter the entire subnetting scheme since we're compelled to use locally-administered address ranges and subnet1 has consumed the entire 10.0.0.0 range.  Can you not alter the mask of subnet1 such that's 10.0.0.0/16 not /8 (i.e. 255.255.0.0 not 255.0.0.0)?

yip

im signing off now for the night i hope we can pick this up again tomorrow

many thanks so far

If that's the case, then approach it as follows -

subnet1 = 10.0.0.0/16 (or 255.255.0.0)
subnet2 = 10.1.0.0/16 (or 255.255.0.0)

... and create the two scopes accordingly.

Note - you don't have to alter subnet2 in the manner I've recommended, I just prefer to see some kind of order to it and, since you're redesigning, we might as well incorporate some kinf of methodology ... your call of course.

I've assumed you're sufficiently familiar with the IP routing and name resolution requirements and have not included any information related to those aspects of your design.

many thanks for this. just one last thing how do i get the pcs in the relevant subnet to get the correct ip scope

just thinking about this and maybe now is the time to change. if i make my main network 10.1.0.0 255.255.0.0 and my second network 10.2.0.0 mask 255.255.0.0 will pcs on subnet 1 then use a router to access subnet ie subnet 1 will not deem subnet 2 local?

hi sorry about this but its me again, i have had a look and there is no way we can change subnet1 its got to stay at 10.0.0.0 255.0.0.0 but i can change subnet 2 no problem. what can we do is there anyway to get this working?

cheeers

cheers for this i had thought of using 172.16.1.0 255.255.0.0 for the second network so i am now working on the router to get that side of things going

Per vsg375's comment and my earlier reference, you'll need to use a locally administered address range.  vsg375 outlined your options and your choice appears fine to me too (assuming the router is, of course, configured correctly).

kingcastle: May I ask why you can't change subenet1?  Is it politics, perhaps not yours to change or a technical reason preventing it?

well its really becuase there is lots of static ip addresses on the lan for printers, vpn's etc and our sister company print to our printers over the vpn to ip addresses

Understood.