Troubleshooting when a virtual machine loses network connection after vMotion

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

This article provides troubleshooting steps for a single virtual machine that loses its network connection after performing a vMotion.

After migrating a virtual machine with vMotion, you experience these symptoms:

• The virtual machine loses its network connection.
• There is no network connectivity to or from a single virtual machine.
• A TCP/IP connection fails to and from a single virtual machine.

Environment

VMware vSphere ESXi 6.x

VMware vSphere ESXi 7.x

VMware vSphere ESXi 8.x

Resolution

Validate that each troubleshooting step below is true for your environment. Each step provides instructions or a link to a document, in order to eliminate possible causes and take corrective action as necessary. The steps are ordered in the most appropriate sequence to isolate the issue and identify the proper resolution. Do not skip a step.

 

To troubleshoot when a virtual machine loses network connection after performing vMotion:

1. Verify the physical network connectivity. From the virtual machine, ping different sources to identify where the issue may be:
    
   • Ping another virtual machine on the same virtual switch and same port group. If this ping test is successful, this should imply there is no issues at source VM level. 
   • Ping the default gateway
   • Ping a target outside the network
   • Check if ICMP is blocked in environment by pinging VMs from different jump boxes also in case of windows VM, try RDP connection if it works to verify only ICMP is blocked.
2. Verify the physical switch setup. For more information, see Loss of network connectivity when Cisco port security is configured on the physical switch (1002811).
    
3. Verify that the correct version of VMware Tools is installed. For more information, see Verifying a VMware Tools build version (1003947).
    
4. If the preceding steps do not resolve the issue and you are experiencing a complete lack of network connectivity from a particular virtual machine, see Troubleshooting virtual machine network connection issues (1003893).
    
5. If you are experiencing network connectivity issues with the ESX host or with multiple virtual machines, see ESX/ESXi hosts have intermittent or no network connectivity (1004109).

Additionally, connection to the default gateway is successful, but connections to other subnets are unsuccessful, then there is an issue in routing/Layer 3. Please contact the network team of your organization to determine why the Layer 3 connections are failing.

Note: If the problem persists after completing the steps in this article:

• Gather the VMware Support Script Data. For more information, see Collecting diagnostic information for VMware ESX/ESXi using the vSphere Client (653).
• File a support request with Broadcom Support and note this Knowledge Base article.

 

Additional Information

 Refer to Packet capture on ESXi using the pktcap-uw tool to collect the packet captures for further analysis.