java.net.noroute_Re: vsphere_client_virgo.log java.net.NoRouteToHos...

On our 6.5 vcsa in  /var/log/vmware/vsphere-client/logs/vsphere_client_virgo.log I'm seeing a lot of errors like this:

[2019-03-12T15:47:50.299Z] [ERROR] data-service-pool-777        70006708 100026 200013 com.vmware.ph.impl.PhoneHomeClientImpl java.net.NoRouteToHostException: No route to host (Host unreachable) com.vmware.vim.vmomi.client.exception.ConnectionException: java.net.NoRouteToHostException: No route to host (Host unreachable)

Just wondering how to fix this?