Unable to ping gateway from virtual machine console

Products

• VMware vCenter Server

Issue/Introduction

• Virtual Machines (VM) cannot ping the gateway from virtual machine console.
  
  
• Most VMs show that they are connected to the network, but are unable to send/receive pings. 
  
  
• Moving VMs to another host seems to resolve the issue for many of the VMs but not all.
  
  
• VMs can ping each other if they are on the same host, vswitch and portgroup.
  
  
• Arps are unanswered on the virtual machine console.
  
  # tcpdump -n arp
  
  
• Unable to view CDP or LLDP info for the vmnic physical switchport.
  
  
• Physical switch is completely locked up, not responding to pings or management UI.

Environment

vCenter 8.x

esx 8.x

Cause

The physical switch learns the virtual MAC addresses flowing across the vmnics to the physical switchports. A locked up physical switch will not function correctly to learn the virtual MAC addresses and switch network traffic.

Resolution

• Reboot the physical switch and validate that virtual MAC addresses flowing across the vmnic physical switchport are being learned.
  
  
• Confirm  virtual MAC addresses are updated in the physical switch CAM MAC address table.
  
  
• Test and validate pings are working for the Virtual Machine gateways.

Additional Information

Enable CDP to get physical switch and switchport information.