id summary reporter owner description type status component version resolution keywords cc guest host 20302 Client ID prevails over MAC based mapping with the NAT Network DHCP server jcb "I've got two Ubuntu (though what matters here is Systemd-Network) guest VMs connected to a NAT Service network with the DHCP service enabled. I have added a static mapping between the guests NIC MAC addresses and their assigned IPs. The NatNetwork-Dhcpd.config file shows what I mean: The same information is reflected in `VirtualBox.xml` (the global config file) though when using `VBoxManage` to set up the mapping I did use the first NIC of each guest to set the mapping hence the `/0` after the guest VM UUID: Now it comes the twist: DHCP Client ID in machines running Systemd-Network use /etc/machine-id to construct it but both machines have the same contents (due to cloning, you know) in this file hence the Client ID sent to the DHCP is always the same (as seen in NatService-Dhcpd.log)... and the dhcp server in the Nat Service returns the same IP address for both guests. Is it a bug, a feature or just RFC compliance? Thanks in advance." defect new network/NAT VirtualBox 6.1.18 DHCP, ClientID, HDCP option 61, DHCPd Linux Linux