I would suggest that anybody who is using the set up to be found here: https://wiki.samba.org/index.php/Configure_DHCP_to_update_DNS_records_with_BIND9 Goes and reads it again, I have updated the page. Why have I updated the page ? Because there was a serious bug with the old one. When I first started using the script, I placed it in /usr/local/bin , it was then suggested that it would be better off in /etc/dhcp/bin , so I moved it. This, it appears was a BAD idea, for if you run 'apt-get update && apt-get upgrade' and isc-dhcp-server gets upgraded, the /etc/dhcp/bin directory disappears, yes, you read that right, the script is removed. How did I find out about this ? Fairly obviously, I ran 'apt-get update && apt-get upgrade' :-( Go and read the wiki page ASAP and don't upgrade until you have fixed the problem. Rowland