Adding ESXi to vCenter after upgradeto version 8.0.3 failing with error "An error occurred while communicating with the remote host."

Products

• VMware vSphere ESXi

Issue/Introduction

After you upgrade vCenter and ESXi host are showing in non responsive state.

Attempting to add host back to vCenter failing with  "An error occurred while communicating with the remote host."

 

Reviewing vCenter and ESXi logs is not showing any concrete error.

 

Collecting packet captures with following commands 

vCenter packet capture
tcpdump -i eth0 -s 256 -w /var/core/vc.pcap 

ESXi packet capture

tcpdump-uw -i vmkX -s 256 -w /var/run/log/esx.pcap

showing that connection keep getting disconnected and re-established.

 

Reviewing Firewall you notice that communication is dropping on one of required ports.

 

 

Environment

vSphere 8.0.3

Cause

Closed required port on firewall 

Resolution

Open required ports on Firewall.

 

For list of all vSphere Ports please see

VMware Ports and Protocols