Discovery failing on Windows workstations (Reverse DNS failing)

[nbadano]

I am having issues with some of the Windows workstations not being able to be discovered in my work's environment. These machines are primarily returning with the "RPC server is unavailable" error, and it occurs most on one of the domains than the other.

I have tried the troubleshooting presented in all the previous postings people have made in the community about the "RPC server is unavailable" error. I have tested the credentials from the MID server machine using the cmd prompt and powershell scripts, used RDC to connect to one of the workstations having the issue from the MID server, confirmed with our network group that traffic wasn't being restricted, checked that the RPC service was up and running, repaired WMI on one of the machines, and tested that the 135 port was open using telnet.

The only thing I can find in common on these machines is that  these machines reverse DNS lookup results in incorrect workstation names being returned. Also when I test the credentials using the powershell script "gwmi win32_operatingsystem -computer  -credential" I get "The RPC server is unavailable" if I enter the IP address of the machine, but if I enter the host name I get a clear response back. Any suggestions on anything I might be missing with this issue?

Edit: I should add that these are machines that were able to be discovered before by ServiceNow, and one of the machines having the discovery issue is my work laptop which has been my main test machine.

[Deepak Ingale1]

Creating DNS entries in DNS server will solve the issue. HOST A entry and PTR records creation with the help of Server Admin team should solve the problem