dhclient: sending a host identifier to the DHCP server

I have a special HDD. It runs FreeBSD 9.1 and contains a bunch of tools that I use when setting up new servers. I hook it up to a new server when I’m working on it. Or I hook it up to a server which is in pain and fix it. I want it to have the same IP address every time. The conventional way to do this is by MAC address.

On your DHCP server, that entry looks like this:

host floater {
  hardware ethernet 00:04:AC:A3:69:E3;
  fixed-address floater.example.org;
}

This is how I’m doing it:

host floater.unixathome.org {
  option dhcp-client-identifier "floater";
  fixed-address floater.example.org;
}

In /etc/dhclient.conf, I put this:

send dhcp-client-identifier "floater";

Works every time.