On ESX/ESXi vSwitch port groups, you experience these symptoms:

• Service Console is unable to ping the gateway IP
• Virtual machine fails to ping gateway
• VMkernel networking issues
• You receive one or more of these errors:
  • Destination Host Unreachable
  • Ping request could not find host IP_address/hostname. Please check the name and try again.
  • Could not open connection to the host, on port ##: Connection failed

1. Verify the Virtual Switch (vSwitch) VLAN ID. For more information, see Configuring a VLAN on a portgroup (1003825).
   
   
2. For Virtual Switch Tagging (VST), ensure that VMNICs uplink to switch port is set to TRUNK MODE.
   
   For External Switch Tagging (EST) ensure that VMNICs uplink to switch port is set to ACCESS MODE.
   
   For more information, see Sample switch port configuration for VLAN and TRUNK MODE (1006628).
   
   
3. Utilize Cisco Discovery Protocol (CDP) information to establish switch port configuration settings and correct port configuration accordingly. For more information, see Cisco Discovery Protocol (CDP) network information via command line and VirtualCenter on an ESX (1007069).
   
   To test this functionality, do a PING and TCPDUMP analysis of ICMP messages. For more information, see Troubleshooting gateway IP connectivity issues via TCPDUMP command (1008017).
   
   
4. If EtherChannel and NIC teaming is configured, verify EtherChannel configuration. For more information, see Sample configuration using EtherChannel, ESX and a Cisco switch (1004048).
   
   
5. Use the ESXi Network Dump Collector in ESXi 5.0 for collecting data and further troubleshooting. For more information, see ESXi Network Dump Collector in VMware vSphere 5.x/6.0(1032051).

• Sample Configuration - ESX connecting to physical switch via VLAN access mode and External Switch VLAN Tagging (EST Mode) (1004127)
• Sample configuration of virtual switch VLAN tagging (VST Mode) (1004074)