vCenter Server logging may show warnings detecting an IP conflict between HCX Fleet Appliances

Products

• VMware vCenter Server
• VMware HCX

Issue/Introduction

vCenter Server is logging the following warning for potential IP conflicts involving more than one HCX appliances.

• To view the error in the vCenter logs, follow the steps below
  • Login to the vCenter via putty/ssh as user root
  • Enable the bash shell by running the command shell.set --enabled true
  • Enter into the bash shell by executing the command shell
  • Navigate to the log file /var/log/vmware/vpxd/vpxd.log

error vpxd[12X45] [Originator@6876 sub=InvtId opID=HB-host-####-#####] Detected IP [:192.0.2.x] conflict between vm [HCX-##########-NE-R1] (moId:vm-#####) nic:GuestInfo.net[5].ipAddress[0] and entity [HCX-##########-IX-R1] (moId:vm-######)"

Note: The above log is an example, and values such as operation IDs, IP addresses, hostnames, and moId's will vary.

Environment

VMware HCX
VMware vCenter Server

Cause

• vCenter is mistakenly flagging IPs as duplicates because it doesn't recognize the isolated nature of these IPsec local tunnels.
• It compares IPs across all inventory items without considering that private IP addresses like 192.0.2.x could be reused across different HCX Fleet appliances.
• The IP address range mentioned is used exclusively within the IX and NE appliances for IPsec local tunnels and is not accessible from the network
• These tunnels utilize the same internal IP pool within each appliance and are isolated, ensuring they are not exposed externally in the network.

Resolution

The vCenter warning regarding the duplicate IP for the IX/NE can be safely ignored.