DHCP IP conf on vmk0 failed with "Unable to Set: Address not available: VSI node (467:VSI_NODE_net_tcpip_instances_vNics_unbind)"

Products

• VMware vSphere ESXi
• VMware Cloud Foundation

Issue/Introduction

• When switching the management network (vmk0) configuration from DHCP to a Static IP and then reverting back to DHCP by DCUI, an error occurs that prevents the system from acquiring an IP address. As a result, the ESXi host becomes unreachable over the network.
  
  
• On the ESXi, the var/run/log/dhclient.log or var/run/log/syslog.log will show errors indicating the VSI node address is not available:

YYYY-MM-DDTHH:MM:SS.MSZ -ERROR dhclient-uw 2413601 [esx@4413] dhclient.c(2738): null pointer
YYYY-MM-DDTHH:MM:SS.MSZ -INFO  dhclient-uw 2413601 [esx@4413] DHCPDECLINE on vmk0 to ###.###.###.### port 67
YYYY-MM-DDTHH:MM:SS.MSZ -INFO  dhclient-uw 2413601 [esx@4413] dhcp_stop_handler reason: FAIL
YYYY-MM-DDTHH:MM:SS.MSZ -INFO  dhclient-uw 2413601 [esx@4413] Unable to Set: Address not available: VSI node (467:VSI_NODE_net_tcpip_instances_vNics_unbind) . Declining offer.

• Additionally, vmkernel.log will show that dhclient-uw is being denied access by the vmkernel access control policy:
  
  ./var/run/log/vmkernel.log:6232:YYYY-MM-DDTHH:MM:SS.MSZ -INFO vmkernel - [esx@4413] cpu1:264447)VmkAccess: 68: dhclient-uw: running in genericDomLocalAuth(16): Vsi node = NET_ADMIN: Access denied by vmkernel access control policy

Environment

• VMware Cloud Foundation 9.1.1
• ESX 9.1.1

Cause

This issue occurs because the Direct Console User Interface (DCUI) spawns the DHCP client (dhclient-uw) in a generic domain that lacks the necessary network administration (NET_ADMIN) access rights.

Resolution

This is a known issue impacting VMware Cloud Foundation 9.1.1. This specific issue does not exist in earlier versions of VMware Cloud Foundation. The issue has been resolved in VCF 9.1.2 and subsequent releases.

Workaround:

To work around this issue and restore DHCP functionality, perform the following steps from the host console:

• Enable the ESXi shell from the Direct Console User Interface (DCUI) and log in to the ESXi host.
  
  
• Execute the following command to disable the stale DHCP session:
  
  esxcli network ip interface ipv4 set -i vmk0 -t none
  
  
• Execute the following command to renegotiate DHCP successfully:
  
  esxcli network ip interface ipv4 set -i vmk0 -t dhcp