For a while now I have been troubleshooting various problems related to multicasting with SCCM 2012 r2. My most recent hurdle has been overcoming awful multicast stream speeds. Production Distribution Points are Windows Server 2012 r2 virtualized on ESX 5.5 using the VMXNET3 network adapter. Networking (so far) has not been able to find any errors or packet loss on the network, so I am thinking maybe the Virtualization layer could be cause of my headaches. I stood up a physical Distribution Point in same network as some physical clients. From testing with the physical Distribution Point the speeds have definitely increased. Speeds were maxing out at about 20 Mbps once all of the client machines joined the multicast stream. I am more confident now that something in the virtualization layer is causing the problem, maybe the virtual switch? I just dont know. Does anyone out there have any thoughts or suggestions from where to go from here? What to check in the virtualization layer, etc? Has anyone else experienced slow multicast speeds when using a virtual ESX host as a Multicast Distribution Point, or even had acceptable speeds for that matter?

-Tony

Many people cite the VMXNET3 adapter and/or its driver as a source of many issues (both ConfigMgr and non-ConfigMgr). I would suggest switching the NIC type and then trying.

Thanks for the input, but I did not have any luck with switching to a different virtual nic. The speeds remained the same. -Tony

On the virtual side of things, Microsoft acknowledged there is a known bug and to get semi usable speeds the WDS registry setting of TpMaxBandwidth needs to be changed from 100 [default] to 1. However, even with that we still have not been able to push past 11%-14% network utilization. boo! :-) 

• Marked as answer by Tony Chirillo 17 hours 40 minutes ago