Easy newbie question about subnets

Subnetting is something that has been getting to me for too long. I
have a network with about 200 printers and workstations. I would like
to logically separate them into lets say 4 distinct subnets, based on
their departments. We are using Windows 2003 server for AD, DNS, and
DHCP. We are using all 3Com and SMC managed switches, not routers.
How would i go about setting up subnetting? Can it be assigned via
DHCP automatically, or do I need to set up manual reservations for each
MAC address and point it to the correct subnet mask? Im just a bit too
confused about this. Any info would be great.

You would need a DHCP server in each subnet or a DHCP relay server. A router
that hands out IP would work as well in each subnet.

<(E-Mail Removed)> wrote in message
news:(E-Mail Removed) ups.com...
> Subnetting is something that has been getting to me for too long. I
> have a network with about 200 printers and workstations. I would like
> to logically separate them into lets say 4 distinct subnets, based on
> their departments. We are using Windows 2003 server for AD, DNS, and
> DHCP. We are using all 3Com and SMC managed switches, not routers.
> How would i go about setting up subnetting? Can it be assigned via
> DHCP automatically, or do I need to set up manual reservations for each
> MAC address and point it to the correct subnet mask? Im just a bit too
> confused about this. Any info would be great.
>

That is basically a good idea, but before you start worrying about DHCP
you need to think about how these subnets are going to communicate with each
other. If you just put them in four different IP subnets without any routing
they will be four isolated networks with no connection to each other or to
the outside world (and DNS and AD will fall apart). You need IP routers
between the subnets and you need a logical system of routes so that the
subnets combine to form a logical network structure.

<(E-Mail Removed)> wrote in message
news:(E-Mail Removed) ups.com...
> Subnetting is something that has been getting to me for too long. I
> have a network with about 200 printers and workstations. I would like
> to logically separate them into lets say 4 distinct subnets, based on
> their departments. We are using Windows 2003 server for AD, DNS, and
> DHCP. We are using all 3Com and SMC managed switches, not routers.
> How would i go about setting up subnetting? Can it be assigned via
> DHCP automatically, or do I need to set up manual reservations for each
> MAC address and point it to the correct subnet mask? Im just a bit too
> confused about this. Any info would be great.
>

So if i were to replace my switches with routers, i should be able to
forward dhcp requests to my dhcp server? When forwarding the requests,
will the DHCP server know which router is forwarding the requests, so
it will know which subnet to assign?

Most routers can handle DHCP relay, which does that sort of thing. The
router receives the DHCP discover broadcast and forwards the request to the
DHCP server. The DHCP server allocates an IP address from the scope for the
correct subnet. It knows what scope to use because the IP needs to be in the
same subnet as the router interface receiving the broadcast. The router
interfaces will have static IPs.

Depending on what equipment you have you may be able to achieve all of
this by programming VLANs.

<(E-Mail Removed)> wrote in message
news:(E-Mail Removed) ups.com...
> So if i were to replace my switches with routers, i should be able to
> forward dhcp requests to my dhcp server? When forwarding the requests,
> will the DHCP server know which router is forwarding the requests, so
> it will know which subnet to assign?
>