Troubleshooting virtual machine TCP/IP issues by pinging the loopback address

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:

This article provides steps to troubleshoot network connection issues by pinging the loopback address (127.0.0.1).

Environment

VMware ESXi 4.1.x Installable
VMware ESXi 3.5.x Embedded
VMware ESXi 4.0.x Embedded
VMware ESX 4.0.x
VMware ESXi 3.5.x Installable
VMware ESXi 4.1.x Embedded
VMware ESX Server 3.5.x
VMware ESX 4.1.x
VMware ESXi 4.0.x Installable
VMware ESX Server 3.0.x

Resolution

To use ping to verify that TCP/IP is working correctly, run the command:

ping 127.0.0.1

The output for a working connection appears similar to:

Pinging 127.0.0.1 with 32 bytes of data:

Reply from 127.0.0.1: bytes=32 time<1ms TTL=128

Reply from 127.0.0.1: bytes=32 time<1ms TTL=128

Reply from 127.0.0.1: bytes=32 time<1ms TTL=128

Reply from 127.0.0.1: bytes=32 time<1ms TTL=128

Ping statistics for 127.0.0.1:

Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

Approximate round trip times in milli-seconds:

Minimum = 0ms, Maximum = 0ms, Average = 0ms

If the you receive an error, TCP/IP is not working correctly.

To resolve this issue, try the following options:

• Ensure that the loopback interface is installed and configured correctly. For more information, see Installing and configuring the Loopback adapter in a virtual machine (1004779).
  
  or
  
• Reinstall TCP/IP. For more information, see the Microsoft article http://support.microsoft.com/kb/299357.
  

  Note: The preceding link was correct as of January 19, 2010. If you find the link is broken, please provide feedback and a VMware employee will update the link.

Additional Information

For more information, see the main article in this series, Troubleshooting virtual machine TCP/IP connection issues (1007842).