[Dnsmasq-discuss] [PATCH] DHCPv6: Honor assigning IPv6 address based on MAC address

[Roy Marples]

On 14/05/2019 14:29, Oliver Freyermuth wrote:
> Same here. In an automated deployment situation, client changes DUID in each phase:
> - PXE (if done via IPv6)
> - Installation time (from ramdisk)
> - Final OS after installation
> This may improve if newer versions of dhcpcd get packaged in installer ramdisks and OS, and also for systemd-dhcp,
> but I am still unaware of any implementation of machine-id as base for the client DUID in dhclient and of course the implementations are all not exactly the same.
> And then there is still the UEFI doing the PXE part, systems with broken machine-id etc.... And of course, dual booting if not set up with identical cliend-DUID.
> 
> In general, my belief is that the RFC was made without real life use cases in mind and hence did not think of these.
> The patch is very helpful to overcome these issues and matches user expectation (when specifying a MAC address in the config file, I want it to be used).

Speaking for dhcpcd (as yay, I am the author) - if the OS presents a 
stable UUID dhcpcd will use that for the DUID:

https://tools.ietf.org/html/rfc6355
https://roy.marples.name/cgit/dhcpcd.git/tree/src/duid.c#n63

So a fully automated deployment using dhcpcd AND a kernel which reports 
a stable UUID then all is good.

But not everyone uses dhcpcd>=7.0.6 with the UUID code in, nor a kernel 
which reports a stable UUID.

There is literally no reason to use dhclient anymore - and hasn't been 
for a number of years.

Roy