Over the last few days I helped migrate some physical infrastructure servers for a client to a brand new Vmware Esx enviroment. Having down this particular task many times I wasn’t really expecting many new issues but in this case its worth pointing out that dhcp can be useful during the conversion of machines that require re-activation of operating systems. The client had purchased the appropriate licensing for the virtual environment and I was expecting one or two of the machines to need re-activating when they were first brought up after virtualisation.
However in all the previous sites I had use of a dhcp server for this initial phase. It was only in this case when the servers booted that we realised they weren’t getting allocated addresses and therefore could not access the web to activate. Luckily in this case I was familiar with the clients router configuration and was able to activate dhcp on a draytek 3300 to provide a pool of addresses during the initial stage of the conversions. The dhcp server worked a charm and facilitated the conversions.
So the moral is – if you are going to need dhcp addresses – even temporarily before conversions just make sure enough addresses are available for the number of servers requiring dhcp addresses during the startup phase.