To start, login to the Server 2003 DHCP host and create a new folder to store the export files. In this example, I created a folder in the root of the C: drive named "migration". Next, open a new Command window and type the following command to export the entire DHCP database.
- netsh dhcp server export c:\migration\dhcp-backup all
- netsh dhcp server export c:\migration\dhcp-scopes 10.200.11.0 10.200.20.0
- dhcp server import c:\migration\dhcp-scopes
In many environments, the DHCP server is hosted on one VLAN but is expected to provide DHCP services to clients across multiple VLANs. In order for the DHCP server to receive the client DHCP broadcast request, your gateway router or switch must redistribute the broadcast packets to the DHCP server. In Cisco IOS network devices, this is accomplished by configuring one or more IP Helper Addresses in the VLAN interface configuration.
The configuration of an IP Helper varies depending on the network equipment being used. The image below illustrates the process of removing and adding IP Helper Addresses to a layer 3 Cisco switch.