My setup consists of a Duo Hub, with the primary H3 connected to Ethernet. All of the Joeys as well as the secondary H3 obtain IP’s/Internet through the primary H3. Bridging on the primary H3 needs to be enabled so that the MoCA and Ethernet ports bridge, while the secondary H3 should have bridging disabled as well as no connection to the internet whatsoever to not cause a network loopback issue.
The alternative (or “authorized”) way to do this is having two Solo Hub’s, and the rest depending on if you want cross-communication between the two H3’s. If you want both setups to be independent of each other, then they each need either their own internet connection or own subnet on the same ISP if you know enough about networking to do so. Another option is to have one H3 with internet and the other without.
Now, if you do want the proper installation with Solo’s but communication between the two DVR’s then they both need to be on the same network, either via Ethernet or WiFi, and they should communicate. But at that point you are better off with a Duo Hub so the communication happens over the MoCA network instead of your own, causing unnecessary congestion.