@rurap Setting up FOG with two network interfaces is kind of an advanced setup. Combining FOG with a NAT router config adds another layer of things that can interfere. I am not saying this doesn’t work per se. It’s just not a default FOG setup and we don’t test those kind of things.
I’d suggest you start by looking at the log files (in
/var/log/fog) to see what information we get from the FOGMulticastManager service when the error happens. Be aware that FOGMulticastManager tries to pick the right network interface and might fail on your system with two NICs.
If that doesn’t yield any success you should look into manually testing multicast as described in the wiki: https://wiki.fogproject.org/wiki/index.php?title=Multicast#Troubleshooting