This is a follow up question from here: How to disable default DHCP on virbr0 and obtain IP from DHCP on host
I have a Ubuntu server 18.04, with Libvirt based Virtual Machines setup over virbr0 bridge. By default libvirt's default DHCP server (dnsmasq) provides IP address assignments through the bridge.
I have replaced the default bridge with a new one "br0" which has one enslaved port on my server "enp7s0". The Virtual Machines are also connected to this bridge, and all 3 interfaces (1 on the server and other 2 on the virtual machines) are communicable using static IP addresses 192.169.x.x/16.
I want to use DHCP on the server to assign IP addresses to the VMs over the new bridge br0.
Taking example of libvirt, the default dhcp server ran by libvirt, on what interface does a VM send DHCP requests to receive IP assignments ? virbr0? in other words, on which interface is the libvirt's dhcp server listening on ?
If I want to deploy my own DHCP server on the Ubuntu server, which interface should the DHCP server listen on "enp7s0" or "br0" ?