I ran into a similar issue after upgrading from vCenter 5.5 to 6.0 U1b (Windows Server) this morning: I'd receive alarms for vsphere-client and vmware-dataservice-sca status changes green -> yellow every 10 - 15 minutes and came across this thread while troubleshooting.

I added the server's IP address under runtime settings "Managed IP Address" and it's been over 1 hour since I received any more alarms... so I'm hoping that did it, at least for my scenario.  This setting is blank by default, which might also explain why it's happening to fresh installs?  I also have a ticket open with VMware to see what they have to say about it...