VMs are unable to communicate when on different ESXi hosts, but can communicate when the VMs are moved to the same ESXi host
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VMs are unable to communicate when on different ESXi hosts, but can communicate when the VMs are moved to the same ESXi host

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Article ID: 414879

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Updated On:

Products

VMware vSphere ESXi

Issue/Introduction

  • VMs on the same subnet and VLAN can ping each other when on the same ESXi host.
  • VMs on the same subnet and VLAN can not ping each other when on different ESXi hosts.
  • Packet captures show ARP or ICMP requests from a VM leave the source VM's host, but the requests never arrive at the destination VM's host.

Cause

The VMs are unable to communicate when on different hosts due to a misconfiguration (usually VLAN) in the upstream network that caused the packets to drop before being given to the destination VM's host. ESXi cannot process or forward a packet that it does not receive.

The VMs can communicate when on the same host (if on the same virtual switch and portgroup/VLAN) because the packets going between VMs in this scenario do not leave the host, so the physical network misconfiguration is not in the datapath.

Resolution

Engage the administrator or team who manages the relevant physical network devices (chassis and/or switches) between the ESXi hosts to correct the misconfiguration.

Additional Information

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