handle duplicate client identifier

glenn.satchell at uniq.com.au glenn.satchell at uniq.com.au
Sat Jun 15 12:25:46 UTC 2019

With Ubuntu Xenial you can remove /etc/machine-id when cloning the 
system and it will be re-created with a new unique value on first boot. 
Similarly once systems are running you can remove the file and reboot. 
See machine-id(5) man page.

Otherwise as Steinar says add

ignore-client-uids true;

dhcpd.conf(5) man page will contain details if it is valid in your 


On 2019-06-14 16:44, sthaug at nethelp.no wrote:
>> Ok, it should be possible, and maybe the best way, to make the
>> machine-id unique on every client. But my question is, if there is a
>> way to prevent the server to use the client-identifier as a key
>> instead of MAC address ?
> In newer versions of ISC DHCP you have "ignore-client-uids" available.
> Not sure if this exists in your version.
> Steinar Haug, Nethelp consulting, sthaug at nethelp.no
> _______________________________________________
> dhcp-users mailing list
> dhcp-users at lists.isc.org
> https://lists.isc.org/mailman/listinfo/dhcp-users

More information about the dhcp-users mailing list