I was deploying vCenter Infrastructure Navigator (VIN) in my lab today and the following error came up after I wanted to check dependencies for a virtual machine:
Access failed, an unknown discovery error has occurred
I rebooted several services but nothing seemed to solve it. Internally I bumped on a thread which had the fix for this problem: DNS. Yes I know always DNS right. Anyway, I used “DHCP” for my VIN appliance and this DHCP server pointed to a DNS server which did not have the IP/name of my ESXi hosts listed. Because of this the discovery didn’t work as VIN tries to resolve the names of the hosts as they were added to vCenter Server. I configured VIN with a fixed IP and pointed the VIN appliance to the right DNS server. Problem solved.