[systemd-devel] Should `MACAddressPolicy=persistent` for bridges/bonds/all-software-devices be reconsidered?

[Thomas Haller]

On Thu, 2022-05-12 at 17:11 +0200, Thomas Haller wrote:
> We are talking here about software device which are always created by
> some tool/software/user. Presumably that creator has plans for this
> interface, and it's not clear why udev is supposed to change such a
> fundamental setting.

I think that's the important point here.

This interface is created by somebody (NetworkManager, networkd,
docker, etc.). In all cases, they did not leave the MAC address
unspecified by accident. They create (or could create) the interface
with the right parameters already.

If networkd wishes to default to MACAddressPolicy=persistent (a
sensible choice!), it may fully do so.

Why is udev doing this? To "help" unknowing users who use `ip link
add`? When it just introduces a race for them.


best,
Thomas