Hey wmaker!
You are probably right. I also see no need to assign eno1 an IP address, since all traffic in + out the host should be routed through the bridge. But that’s also my 2 cent.
And most definitely, you have to create the xml file for kvm and make your bridge known! I missed this (I would say fundamental step) is missing in the above guide! This is crucial.
As for netfilter all I can tell you is my virtual machines (and I tried to setup a couple) would not get any IP traffic at all until I did this. Maybe it’s the other way round and you need netfilter to do be loaded. But then again, this is where Ubuntu does it’s magic and I really don’t have the time to go that deep. I’d prefer I had to proactively do my configuration, than “magic” happen under the hood.
I hope we can help with our comments