I'm not really sure how everything is set up but it all works for MRV.
In my bedroom:
HR20-700 -- Ethernet cable to SwitchB
HR22-100 -- Ethernet cable to SwitchB AND ethernet cable from white box(DECA) to switchA
HR44-500 -- no cables to switch at all (but this receiver says 'SWiM Connected. Internet connected')
SwitchB -- ethernet to SwitchA (in separate room with all Internet equipment hard-wired)
In my living room:
HR22-100 -- ethernet cable to SwitchC
HR21-100 -- ethernet cable to SwitchC
SwitchC -- ethernet cable to SwitchB
In my Office(room with Internet)
Verizon FiOS from street into Astaro Security Gateway 110/120
SwitchA into ASG LAN port
SwitchB into SwitchA
Cisco EA6500 WiFi router (in bridge mode) into SwitchA -- ONLY FOR WiFi handhelds (no DVR's connected via WiFi)
I think that's it. Like I said, MRV is working (although when I reboot my DECA DVR, everything has to be rebooted or i have no MRV). I just realized that one of my DVR's is connected via DECA today when investigating.
Let me know if you need any further info.