Cannot add ESXi host to the vCenter Server inventory

Products

• VMware vSphere ESXi

Issue/Introduction

When adding an ESXi Host to vCenter Server, alert is shown stating: "Cannot contact the specified host ###. The host may not be available on the network, a network configuration problem may exist, or the management services on this host may not be responding."

In vsphere_client_virgo.log, it shows:

[ERROR] http-#-440       70061992 105335 200160 com.vmware.vsphere.client.host.impl.HostMutationProvider          Error when validating host connection com.vmware.vim.binding.vim.fault.NoHost: Cannot contact the specified host (hostname / ip). The host may not be available on the network, a network configuration problem may exist, or the management services on this host may not be responding.
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
        at java.lang.Class.newInstance(Class.java:442)

In vpxd.log, it shows:

warning vpxd[06757] [Originator@# sub=IO.Connection opID=#-auto-8zdo-h5:#-9d] Failed to connect; <io_obj p:0x00007f#, h:-1, <TCP '0.0.0.0 : 48560'>, <TCP 'HostIPAddress : 443'>>, e: 104(Connection reset by peer), duration: 120006msec
info vpxd[06757] [Originator@# sub=IO.Connection opID=#-auto-8zdo-h5:#-9d] Failed to shutdown socket; <io_obj p:0x00007f#, h:-1, <TCP '0.0.0.0 : 48560'>, <TCP 'HostIPAddress : 443'>>, e: 9(shutdown: Bad file descriptor)

Environment

VMware vCenter Server 7.x
VMware vCenter Server 8.x
VMware vSphere ESXi 7.x
VMware vSphere ESXi 8.x

Cause

• The network communication between ESXi and vCenter is abnormal.
• Port(s) 902 or port 443 may be blocked by the firewall.

Resolution

Troubleshoot the network issue between the vCenter Server and the ESXi host, follow these steps: 

1. SSH into the vCenter and check if you can connect to ports 902 and 443.

   • Run the following commands from a vCenter Server SSH session:

     • curl -v telnet://<HostIPAddress>:443

     • curl -v telnet://<HostIPAddress>:902

   • Run the following commands from an ESXi host SSH session:

     • nc -zuv <vCenterServerFQDN> 902

     • nc -zv <vCenterServerFQDN> 443

2. If the ports are blocked the response will be blocked for the previous commands. To resolve, open ports 902 and 443 between the vCenter Server and the ESXi host.

Additional Information

VMware Ports and Protocols