Management I/O

The management interface was defined during the creation of the VM:

<interface type='direct'>

<mac address='52:54:00:fc:ea:99'/>

<source dev='eno3' mode='bridge'/>

<model type='virtio'/>

<address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>

</interface>

The creation of this interface automatically adds a MAC address which may be less than random. That is, should another KVM host be in the same collision domain, without changing this parameter there could be a conflict, making the management access unreliable.

The OUI registered for QEMU is 52:54:00, and the following can be used to automatically generate and output a random MAC address to use instead and hopefully avoid this issue:

MACADDR="52:54:00:$(dd if=/dev/urandom bs=512 count=1 2>/dev/null | md5sum | sed 's/^\(..\)\(..\)\(..\).*$/\1:\2:\3/')"; echo $MACADDR