[PVE-User] Proxmox VE 7.0 (beta) released!

Thomas Lamprecht t.lamprecht at proxmox.com
Tue Jun 29 12:31:14 CEST 2021

On 29.06.21 12:06, Mark Schouten wrote:
> Hi,
> Op 29-06-2021 om 11:46 schreef Thomas Lamprecht:
>> Do you have some FW rules regarding MAC-Addresses or the like?
>> As the MAC-Address selection changed in Proxmox VE 7 due to new default
>> n systemd's network link policy, as listed in our known issues[0].
> There is no firewall configured on this cluster. On Stoiko's advice, I changed the systemd-link-settings and now everything works again.

Ah yeah, that advice was not posted to the list initially so I did not saw that...

> I do not completely understand why that fixes it though.  Commenting out MACAddressPolicy=persistent helps, but why?

Because duplicate MAC addresses are not ideal, to say the least?

I.e., quoting the second part of my original reply again:

> It's now not the one of the first port anymore, but derived from interface
> name and `/etc/machine-id`, which in combination should be unique but also
> persistent.
> But, for some ISO releases (4.0 to 5.3) the machine-id for the installed host
> was not always re-generated, which could result in duplication of a MAC for
> identical named interfaces on two hosts.
> We try to actively catch and fix that on upgrade by checking if the ID is one
> of the known static ones (it's just a handful of possible IDs) on upgrade.
> But if one cloned an machine (e.g., a colleague run into this in a demo
> virtualized PVE test clusters they cloned from a template) that ID will be
> duplicated and thus make problems.
> That could be easily checked by comparing the `/etc/machine-id` content and
> be fixed by re-generation[1].

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