LXC. how to replace a long machine identifier with a mac address in dhcp


Feb 3, 2023
I'm using a container based on Ubuntu 23 and I want to receive the container's mac address instead of the identifier in the dhcp. how to force them to give away mac address? netplan configs do not affect the operation of the network. the config in networkd is overwritten by pve.
and one more thing, I don’t even receive the machine identifier in dhcp, instead there is a completely different identifier. I couldn't find it

cat /etc/machine-id

after reboot or
networkctl renew eth0

even after re-creating the dbus-uuidgen ID --ensure=/etc/machine-id, there is a completely different identifier in dhcp again
Last edited:
the machine id should never be sent out into the network, only derivatives like you are probably seeing [0].
You can configure your machine to send out a hardware based identifier [1], but I haven't tried that myself.

Regarding the overwritten config, this behavior can be changed by creating /etc/network/.pve-ignore.interfaces.

[0] https://www.freedesktop.org/software/systemd/man/latest/machine-id.html
[1] https://superuser.com/questions/1553094/force-to-use-mac-address-as-dhcp-client-id-on-debian-buster
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