Verify your DNS info is correct for each system
During my studies at Dawson College I ran into his issue a lot while trying to set up my virtual lab environment. Using both VirtualBox and VMWare. Here is a basic layout of my virtual lab environment:
|System Name||IP Address||Function||OS|
|OLYMPUS||192.168.12.250||DC. AD, DNS||Server 2012 Datacenter|
|ARES||192.168.12.251||TBD||Server 2012 Datacenter|
|HERMES||192.168.12.5, 18.104.22.168||Gateway, IIS||Server 2012 Datacenter|
|ZEUS||192.168.12.10||Remote Service Control||Windows 8.1 Enterprise|
I chose the Greek Gods as they are of interest to me. OLYMPUS, Home of the Gods, being the Domain Controller, Active Directory and DNS, where everything is stored. HERMES, the Messenger God, is my gateway and IIS server, ARES, God of War, whose function in my environment has yet to be determined, And ZEUS, God of all Gods, is the Controller of all Gods.
Now using VMWare in the lab at school. the issue was that ZEUS, using RSAT tools for 8.1, was able to see OLYMPUS, but not HERMES. It gave 2 errors after trying to connect to the remote server:
Error HERMES: Refresh failed with the following error: The RPC server is unavailable.
Error : Configuration refresh failed with the following error: The metadata failed to be retrieved from the server, due to the following error: The WinRM client cannot process the request because the server name cannot be resolved.
I tried to connect to ARES, and was able to successfully connect without issue (After enabling the Firewall Rules for Remove management). I needed all 3 servers to communicate with Zeus however as I need my remote Management system to do all the work without touching the servers.
After a few hours of messing with it, I decided that since ARES was readable I would enable the gateway on it. However once I had done that, it seemed to work OK, but I could not get Hermes to run as a regular server.
At home I put everything into VirtualBox as it is an easier system to use. this time however ZEUS could only connect to OLYMPUS and Not ARES or HERMES, giving again the same messages.
It took another 8 hours to figure out the issue is not with RPC or the Firewall, but with DNS. When you make your server a Gateway, it tells DNS to use your External IP address, which is why I could not access HERMES in VMWare, I wans on the internal 192.168.12.0 network which DNS was saying HERMES was on the Schools Network, its outside facing nic card. This caused the server to be unreachable. When I went home, as the network has not change to the 192.168.1.0 network for outfacing. and my internal facing IP was using Virtualbox so it was now 192.168.56.0 network, so neither server managed to work at all.
After going in and changing the DNS settings for the domain and its hosts, then flushing the DNS on the Control system, everything worked.