On a separate note, ifup / ifdown no longer works on my installs either. Not sure why that should be the case though. It may be worth noting that the cause of being issued with different IP addresses on reboot was because I carried out the install on one Pi and then moved the SD card to another.

I've also tried endless searching for information regarding DHCP3 but none of what I find relates to my installation. I've tried uncommenting it and substituting my hardware address but it made no difference. The only line which looks like it may be what I'm looking for is commented out and is as follows: The comments within it say that it is a 'configuration file for /sbin/dhclient, which is included in Debian's dhcp3-client package'. What I do have is a file /etc/dhcp/nf which looks like it's a DHCP client configuration file. RetroPie is the best emulator for the Raspberry Pi SBCs. It provides a modern and user-friendly interface. It is the best OS for emulating retro games on a single-board computer like Raspberry, ODroid C1/C2, or even PC. Isn't it for running a DHCP server anyway? It is another Raspberry Pi OS that has been built based on the Debian software library. Unfortunately I don't have that configuration file on my Pi.