I had a hard drive go bad on a rendering server. I rebuilt the server with a new hard drive. I can send a job to it fine with net render but when I try to resolve servers in the DR dialouge box, Vray says ??? in the I.P. address area. I have deleted the server and added new, I have restarted all machines and reset my cable router. I can see it fine and I know what the I.P. address is but Vray cant seem to find it. This is a XP64 server, I dont know if that has and reason.
Sounds like a simple thing that could be overlooked - but have you pointed your slaves Max/Vray install to the proper licensing server under render dialog?
you might try the computer name instead of IP
I did the restart process once more and it seem to be good. Its always something!!! Thanks for the ideas.