Unable to ping the gateway from the ESXi host

Products

• VMware vSphere ESXi

Issue/Introduction

When testing an ESXi host management network configuration via the Direct Console User Interface (DCUI), the host is unable to ping the default gateway or DNS servers. This condition often results in the host showing as "Not Responding" in vCenter Server. Packet captures may show outbound ARP requests leaving the host but no corresponding ARP replies returning from the upstream physical network:

Environment

VMware ESXi 7.x
VMware ESXi 8.x

Cause

The network configuration is inconsistent with the physical switch port configuration, or the physical NICs are not in a connected status. This can be caused by:

• VLAN tag mismatches.
• Physical port failures or upstream switch blocks.
• Inconsistent LACP/LAG configurations.

Resolution

1. Verify Physical Connectivity: Ensure cables are seated and optics are approved. Run the following command to verify status: following Confirm both Admin and Link status are "Up."

   esxcli network nic list

2. Validate Layer 2 Configuration: Ensure the physical switch port configuration matches the ESXi host (VLAN ID, MTU, etc.).
   • Perform a vmkping to another host on the same subnet to isolate the gateway: 

     vmkping -I vmk0 [target_IP]

   • If no ARP replies are received, verify the VLAN ID and subnet mask for vmk0.
     
     
   • Perform packet capture on the uplinks to see if traffic can be seen on the VLAN. 

     pktcap-uw -- uplink vmnicX -- vlan <VLAN ID> -- dir 1 -c 2

   • Identify which VLANs are visible for each uplink.  

     esxcli network nic vlan stats set -n vmnicX -e true
     esxcli network nic vlan stats get -n vmnicX

     Note: Disable VLAN stats after troubleshooting

     esxcli network nic vlan stats set -n vmnicX -e false

   • Confirm whether the customer is using LACP, as it is only supported on vSphere Distributed Switches (vDS), not Standard Switches.
     
     
3. Bypass Isolated Paths: If an upstream block is suspected, try provisioning alternative adapters (e.g., vmnic0 or vmnic2) and moving the management traffic to a different validated VLAN.
4. Download Latest Updates: Ensure the host is running the latest network driver versions.See Download Broadcom products and software for steps to download.

Additional Information

Testing VMkernel network connectivity with the vmkping command