ESXi host unable to ping default gateway and enters Not Responding state during cluster addition

Products

• VMware vSphere ESXi

Issue/Introduction

When adding a new ESXi host to a cluster, the host may fail to communicate with its default gateway and enter a "Not Responding" state in vCenter Server. This behavior typically indicates that management traffic is being routed through physical uplinks that have underlying network connectivity or configuration issues at the physical switch layer.

• New ESXi host is unable to ping its default gateway from the Direct Console User Interface (DCUI).
• Host enters a Not Responding state in vCenter Server shortly after being added to a cluster.
• Management traffic is configured on specific uplinks (e.g., vmnic6/vmnic7).
• vmkping from the host to the gateway returns 100% packet loss.

Environment

VMware vSphere ESXi

Cause

The physical network infrastructure or port configuration associated with the active management uplinks is unable to successfully carry management traffic or provide ARP responses for the gateway.

Resolution

Follow these steps to isolate the network path and restore connectivity:

1. Log in to the affected host via the DCUI or tech support mode.
2. Verify the physical link status of all network adapters by running the following command: esxcli network nic list
3. Identify the current uplinks associated with the management VMkernel interface (e.g., vmk0, or whichever vmkX is configured for management traffic in your environment):
   • Run esxtop, press n for network, and locate specific management VMkernel interface to see its associated vmnic..
4. Temporarily migrate the management traffic to alternative, validated physical uplinks (for example, moving from the currently failing uplinks to known functional ones):
   
   
   • If using a Standard Switch, modify the vSwitch properties in the DCUI under Configure Management Network > Network Adapters.
   • If using a Distributed Switch, ensure the port group is configured to use functional uplinks.
5. Test connectivity by pinging the default gateway again from the DCUI.
6. Once connectivity is restored and the host is online, engage the Network Team to audit the physical switch ports and VLAN trunking configuration for the original, failing uplinks.

Additional Information

Testing VMkernel network connectivity with the vmkping command

Unable to ping the gateway from the ESXi host