Virtual Machines Cannot Ping other Virtual Machines intermittently

Products

• VMware vSphere ESXi

Issue/Introduction

Virtual machines on several different servers are having intermittent trouble pinging each other or other machines on the network. What is wrong?

Environment

VMware ESX Server 1.5.x
VMware ESX Server 1.x

Resolution

To help diagnose the cause of the problem, run this command on the console operating system of each ESX Server computer hosting a virtual machine that is having network trouble.

hostname --ip-address

If the command prints 127.0.0.1, the ESX Server computer was not correctly connected to the network at the time the ESX Server software was installed. As a result, the file /etc/hosts on the console operating system was not set up correctly. Examine that file. Notice that the local machine's external name is on the line beginning with 127.0.0.1.

To resolve the problem, edit /etc/hosts, and move the local machine's external name to a new line beginning with its external IP address. For example, if the name of the machine is volley and its external IP address is 192.168.1.7, the resulting file will be similar to this:

127.0.0.1localhost.localdomain localhost

192.168.1.7volley.mydomain.com volley