MS DHCP Server with Multiple VLans on Cisco Router

MS DHCP Server in a VLAN Environment

1.use multiscpoe option in MS DHCP Server.
2.Create scopes on the dhcp server with address pools like "192.168.1.0/24 ,192.168.2.0/24,....for each vlan.
3.create vlan interfaces on the router for each vlan, assign ip addresses and masks to the interfaces according to your DHCP scopes.
4.configre "ip healper address" on the router/L3 switch.
5. you are done.

Configuring DHCP/BootP relay agent on Cisco Router

Configuring a Router to forward DHCP/BootP is very simple. Configure an IP helper-address pointing to the DHCP/BootP Server, or pointing to the subnet broadcast address of the network the server is on.

To forward the BootP/DHCP request from the client to the DHCP server, the ip helper-address interface command is used. The IP helper-address can be configured to forward any UDP broadcast based on UDP port number.

For Example:

interface Ethernet0
ip address 192.168.2.1 255.255.255.0
no ip directed-broadcast
!
interface Ethernet1
ip address 192.168.1.1 255.255.255.0
ip helper-address 192.168.2.2 
ip helper-address 192.168.2.3 

!--- IP helper-address pointing to DHCP server
===============================================

Reference from cisco and techrepublic website.