During backup job or during manual snapshots observed "An error occurred while communicating with remote host"

Products

• VMware vCenter Server

Issue/Introduction

We see host communication error:

• During VM snapshot operation. 
• While deploying new VM to the host

Environment

7.x

8.x

Cause

The error is triggered by a breakdown in the Management Plane communication between the vCenter Server and the ESXi host.

1. The physical network adapter (vmnic) dedicated to the Management Network (vmk0) is experiencing intermittent link flaps or instability.

2. The ESXi host is unable to consistently resolve the Fully Qualified Domain Name (FQDN) of the vCenter Server, or vice versa, preventing a successful SSL/TLS handshake for the snapshot command.

Resolution

Refer Error: "Cannot contact the specified host" when reconnecting the host to fix physical NIC and DNS connectivity.