Sigh...Debian/Ubuntu people apparently felt it necessary to write their
own dhclient-script which ignores the exit value from dhclient-enter-hooks. The result is that an Ubuntu node in an inner elab can wind up with a 18.104.22.168 nameserver if the DHCP replies come in in a particular order. So we, um..."work around" that situation. Also, ethtool is in a different location.