If you are still using Windows 2008 for vCenter Server. You may see ESXi hosts lost connection back and forth on vCenter Server after recent Windows pathing. It’s not something like a heartbeat lost for a few seconds. ESXi can takes minutes to back online.
You can see similar logs in vpxd.log:
2018-08-03T09:24:23.337-04:00 error vpxd [Originator@6876 sub=HttpConnectionPool-000000] [ConnectComplete] Connect failed to <cs p:00000000200ed300, TCP:XXXXXXXXXXXXXXXX:443>; cnx: (null), error: class Vmacore::SystemException(Only one usage of each socket address (protocol/network address/port) is normally permitted)
2018-08-03T09:24:23.337-04:00 error vpxd [Originator@6876 sub=Vmomi opID=HB-host-28@307067-1d257f9c] [VpxdClientAdapter] Got vmacore exception: Only one usage of each socket address (protocol/network address/port) is normally permitted
2018-08-03T09:24:23.338-04:00 error vpxd [Originator@6876 sub=Vmomi opID=HB-host-28@307067-1d257f9c] [VpxdClientAdapter] Backtrace:
–> [backtrace begin] product: VMware VirtualCenter, version: 6.0.0, build: build-3634793, tag: vpxd
–> backtrace vmacore.dll[0x001C599A]
–> backtrace vmacore.dll[0x0005C8BF]
–> backtrace vmacore.dll[0x0005DA0E]
That’s because your Windows server installed one of following patches.
The fixes are the following.
If you installed KB4338818, please install July 18, 2018—KB4338821 (Preview of Monthly Rollup)
If you installed KB4338823, please install Improvements and fixes – Windows 7 Service Pack 1 and Windows Server 2008 R2 Service Pack 1 (KB4345459)