Cisco – How to Configure DHCP to Assign a Specific IP Address to a MAC Address in IOS

I don't think it's possible to do what you want to do. If it would be possible, it would be something like this:

ip dhcp pool MAC1
  relay source 10.10.0.0/24
  relay destination 192.0.2.NEW
  client-identifier 0122.2222.2222.01
...
ip dhcp pool REST
  relay source 10.10.0.0/24
  relay destination 192.0.2.OLD

But it was not accepted in my lab box:

lab(dhcp-config)#client-identifier 0122.2222.2222.01
% This command may not be used with network, origin, vrf or relay pools.

You can however configure two helper-addresses and filter the requests at the DHCP server, so that 'old' excludes replying to those 5 MAC addresses and 'new' only replies to them.

But maybe you simply need more isolated lab environment, at least separate logical interface.

You could also create interim DHCP server, which forwards requests further based on the MAC addresses, it wouldn't be very hard exercise, probably 2-3h including research for me. But would you want your production to rely on this new script, I certainly would not want it to.

is there is a way to act as an Cable Modem CPE, download the configuration file from the DHCP [Option 67] and load it.

You are asking about Autoinstall in Cisco IOS:

• Router (with blank NVRAM) pulls an address from DHCP
• Router uses DHCP Options 3, 6, 66, 67, and 150 to reconfigure itself via TFTP

I also found a pretty good blog post on autoinstall

If you're looking for a tool to perform Autoinstall, check out freeztp; it's written in Python and uses a series of commands to set up configurable templates for IOS routers and switches.

Thank you for asking about this feature, I completely forgot it existed.