vCenter vpxd service fails to start due to duplicate VMkernel IP address conflict on ESXi hosts
Article ID: 418108
Updated On:
Products
Issue/Introduction
The vCenter Server service (vpxd) fails to start after detecting an IP address conflict between ESXi hosts on the same VMkernel network.
In the vpxd logs, the following messages may appear:
Detected IP [iSCSI2:192.168.1.100] conflict on hosts <hostname1> and <hostname2>.
basic_string: construction from null is not valid
The issue typically occurs when two or more ESXi hosts are configured with identical VMkernel IP addresses (for example, vmk2 for iSCSI or vMotion).
As a result, vCenter cannot load the host inventory properly and the vpxd service stops during initialization.
Environment
vCenter Server 7.x
vCenter Server 8.x
Cause
The issue is caused by a duplicate VMkernel IP address across two or more ESXi hosts. When vpxd starts, it validates network configurations for all managed hosts. If duplicate VMkernel IPs are found, the inventory validation process fails and vpxd terminates unexpectedly.
Resolution
To resolve the issue:
1. Identify the conflicting hosts with one of the following methods:
From the vpxd logs, locate the IP conflict message:
Detected IP [iSCSI2:172.16.x.x] conflict between host-XXXX and host-YYYY
Note the hostnames or IDs mentioned.
Verify IP configuration on each host via esxcli:
esxcli network ip interface ipv4 get
Look for duplicate IP addresses assigned to the same VMkernel (e.g., vmk2).
2. Assign unique VMkernel IPs:
3. Edit the VMkernel interface on one of the conflicting hosts:
esxcli network ip interface ipv4 set -i vmk2 -I <new-unique-IP> -N <netmask> -t static
Example:
esxcli network ip interface ipv4 set -i vmk2 -I 192.168.1.105 -N 255.255.255.0 -t static
4. Validate connectivity and gateway:
esxcli network ip route ipv4 list
5. Restart vpxd on the vCenter Server:
service-control --start vpxd
6. Confirm vCenter services are healthy:
service-control –status
7. Validate inventory load:
a. Log in to vSphere Client and confirm that all hosts and networks display correctly.
b. Verify that the iSCSI or vMotion networks are functioning.
Additional Information
Always ensure unique VMkernel IP assignments across all ESXi hosts in the same network segment. It is recommended to use IP management documentation or host profiles to avoid duplicates.
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