Question : VLAN Setup with 2 Subnets and 1 DHCP Server

I am in the planning phase of overhauling my company’s network infrastructure.  I want to setup 2 VLANs with different subnets.  VLAN1 will have a 172.16.244.X  address and VLAN2 will have a 172.16.245.X address --  I only want to use one DHCP server.  Ultimately, users on VLAN1 and VLAN2 will arrive to the same information because the servers have dual NIC cards – the purpose of this setup is to optimize network traffic.  However, I am somewhat confused on how to implement this scenario:

Where would I input the second subnet for VLAN2 (172.16.245.X)?

Will I be able to pull this off with two 3Com 4200G Gigabit Switch?

I have heard about configuring an IP-Helper forwarding for DHCP.  How exactly is this done in general?

Answer : VLAN Setup with 2 Subnets and 1 DHCP Server

If you want to use vlans, there has to be a layer3 device in the mix so that vlan 1 can talk to vlan 2 (layer 3 switch or a router). I know nothing about 3com devices so not sure if this an L3 switch or not. If you have split the nics on the server (one on each subnet) then this will suffice as long they plug into the two seperate vlans.

on the dhcp server, make two scopes, one for each vlan/subnet ip address range you want to allocate.

Ip helper-addresses asre used when there is no dhcp server available on a specific subnet/vlan. The helper-address forwards requests to specified ip addresses where a dhcp server can be found.