vCenter Server reports false-positive IP conflict warnings for IPv6 link-local addresses via GuestInfo

Products

• VMware vCenter Server

Issue/Introduction

vCenter Server logs and third-party syslog data (collecting /var/log/vmware/vpxd/vpxd-[nnn].log) may report the following warning as a potential IP address conflict for one or more ESXi hosts, Similar warnings may also be observed for virtual machines:

<timestamp> error vpxd[12345] [Originator@6876 sub=InvtId opID=########-######-auto-#####-h5:########-##-######] [VpxdInvtId::CheckIp] detected IP [:192.168.##.##] conflict between host [host-a.example.domain] (moId:host-##) nic:NetworkInfo.vnic[1].ipAddress and entity [host-b.example.domain] (moId:host-##)

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

Environment

• VMware vCenter Server 7.x / 8.x
• VMware vSphere ESXi 7.x / 8.x
• VMware Tools (all versions)

Cause

vCenter Server performs a global comparison of all IP addresses reported by entities in the inventory. It does not natively distinguish between globally unique addresses and link-local (fe80::/10) or private IP ranges (10.x.x.x,192.168.x.x) that may be validly reused in separate Layer 2 segments or Remote Office/Branch Office (ROBO) environments.

Resolution

These warnings are false positives when they involve fe80:: addresses or isolated networks and can be safely ignored. To manage these alerts:

1.  Verify the reported conflict involves a link-local address (fe80::) or an IP in a known isolated network.
2.  Review the VM or Host MAC addresses to ensure they are unique.
3.  Acknowledge the alarm in the vSphere Client and select "Reset to Green".
4.  To suppress future notifications in Aria Operations for Logs, update the alert filters to exclude "vpxd" log strings containing the specific IP range or the term GuestInfo.net.

Additional Information

For more information on configuring management networks for ESXi hosts, see Configuring VMware ESXi Management Network from the direct console