I've begun to test multicast deployments but am sort of at a standstill.

The multicast image deployment should have begun on 4 of my test systems per the console, as well as I clicked the Deploy now button after they sat there for a couple of minutes with no change.

The 4 clients are all sitting at a screen with "Multicast deployment will start automatically at the end of the wait time scheduled by the admin under deployment settings"

Server side, the systems report as follows

Deployment Status:  Waiting for target response

Post Deployment Status: Yet to start

Unicast Deployments have worked without issue.

Here is the current layout of my environment.

Router/Switch Vendor: Unifi

Server Subnet: 192.168.4.0/24

Client Subnet: 192.168.3.0/24

IGMP Snooping: Enabled on both subnets

After a while the server eventually showed the status as failed, however the clients continue to sit at the screen without a way to restart them remotely.

Is there perhaps a specific firewall port that I need to add to the firewall ruleset which is only used for multicast? 

Also, is there a way to embedd a VNC client into the DS WinPE Image as well as have the system's IP reported in the Deployment Details?

Thankfully this is a test deployment at the moment, but I could see this being somewhat of a problem in production if the only way to recover a system was via VPro or SneakerNet.