But I'm talking about another use for virt-managed KVM VMs: I like to simulate setups that are independent of the local network, and setups Keep in mind that you can make any network you want on any virtual machine using either bridging or virtual networks..
that are shut off from most of the world. (Also sometimes for quick "create, run release engineering/qa scripts, destroy" purposes.) This might help http://wiki.libvirt.org/page/Networking
I then like to have a rapid procedure that stands-up these configurations.
I would rely on virt-manager as much as possible, its very easy and fast. You can use it to create/destroy virtual networks too.
For such a simulation the default NAT works well, and I'm trying to give it a transportable configuration with less volatile ip
I would urge you to use a proper router. For example, setup a virtual openwrt or vyos to run your virtual network gateway, dhcp, dns, routing, etc. Then stick your hosts behind it.
addresses and some repos. The repository can be anywhere that is reachable by the guests. I would choose the kvm host server because its local and fast.
I'm heading to w21 right now. See you there!