Virtual Machine is unable to communicate with other virtual machines on the same NSX segment or VLAN

Products

• VMware NSX
• VMware vSphere ESXi

Issue/Introduction

A virtual machine is newly configured or reconfigured on a NSX segment or VLAN. The virtual machine is unable to communicate with virtual machines or the default gateway IP address. Ping tests and other network traffic from the virtual machine may fail to reach the destination. The ARP table on the virtual machine may not show expected MAC addresses. The virtual machine is powered on and the vNIC is connected to the NSX segment or VLAN network.

• Use arp -a to check ARP table on virtual machine.
  
  
• Do a ping #.#.#.# test to the virtual machine's default gateway to test connectivity.

Environment

• VMware vSphere
  
• VMware NSX

Cause

The IP address or subnet mask is misconfigured on the virtual machine.

Resolution

Check the virtual machine IP address and subnet configuration. Compare the virtual machine IP and subnet configuration to another virtual machine on the same NSX segment or VLAN. Verify the virtual machine is on the correct NSX segment or VLAN. Configure the virtual machine IP address and subnet mask to be in the correct IP address range and subnet mask.

Additional Information

Multiple causes are possible for virtual machine network connectivity failing. Verifying the virtual machine IP address, subnet, default gateway, and DNS configuration should be an early step in troubleshooting.
Troubleshooting virtual machine network connection issues

Internet Standard Subnetting Procedure
Variable Length Subnet Table For IPv4