Cockpit: cannot change MAC address of bridged network interface

Latest response

After a VM install, I change the interface type to 'Bridge to LAN', with a source of 'bridge0', and default model ('Linux, perf'). This works fine if I don't modify the MAC address. If I boot the VM and run 'ip a', this shows that the interface name is 'enp1s0', as expected, and that the interface is UP, and has a new IP address from an external DHCP server.

However, if I attempt to change the MAC address, 'ip a' shows a new interface name of 'en7ps0', which is DOWN.

This is repeatable - going back to the original MAC address gives me a working enp1s0, while setting a different MAC address gives enp7s0, which is DOWN.

Any ideas? Is this a known bug, or am I doing something wrong? This is on RHEL 8.5, Cockpit 251.1.

Responses

Just to confirm, are you changing the mac address on the KVM host, right?

Can you check the contents of the following files: (on the guest)

/etc/sysconfig/network-scripts/ifcfg-enp1s0
/etc/udev/rules.d/70-persistent-net.rules

If the old mac address shows up there, please update as required.