Host Connection Failure due to Duplicate FQDN in DNS

Products

• VMware vSphere ESXi

Issue/Introduction

• Attempting to add ESXi host to vCenter fails with an error: "Host has a Datastore that conflicts with an existing Datastore in the Datacenter"     

         

• In var/log/vmware/vpxd/vpxd.log, entries look similar to below:

  YYYY-MM-DDTHH:MM:SS.info vpxd[01234] [Originator@6876 sub=vpxLro opID=5a6b7c8d] [VpxLRO] -- BEGIN task-internal-1234 -- HostSystem.Reconnect -- 52a1-b2c3-d4e5
  YYYY-MM-DDTHH:MM:SS error vpxd[01234] [Originator@6876 sub=HpHelper] [VpxdHostSync] Duplicate FQDN detected for host: esxi-01.example.com. Reverse lookup returned multiple records.
  YYYY-MM-DDTHH:MM:SS info vpxd[01234] [Originator@6876 sub=vpxdVmomi] Result:
  (vim.fault.DatastoreConflict) {
     faultCause = (vmodl.MethodFault) null,
     faultMessage = <unset>,
     name = "vsanDatastore",
     datastore = 'vim.Datastore:datastore-101'
     msg = "An error occurred while communicating with the remote host. Host has a Datastore that conflicts with an existing Datastore in the Datacenter."
  }
  YYYY-MM-DDTHH:MM:SS error vpxd[01234] [Originator@6876 sub=HostAccess] Failed to reconnect host [esxi-01.example.com]: vim.fault.DatastoreConflict

 

• nslookup from vCenter to ESXI Host gives output below:  

  root@VCSA [ ~ ]# nslookup ##. ##.###.### (ESXI_IP Address)
  209.###.##.##.####        name= esxi-01.example.com
  209.###.##.##.####        name=esxi-01.example.com  <-- Duplicate Entry
   
  nslookup using IP  (Duplicate Entry for FQDN)
  
  nslookup using FQDN (Single IP shown below using FQDN)
  
  root@VCSA [ ~ ]# nslookup ##. ##.###.### (ESXI_FQDN)
  127.0.0.1
  127.0.0.1###
  Non-authoritative answer:
  #################### (FQDN)
  Address: ##.##.###.###

 

 

Environment

VMware vCenter Server

Cause

• The primary cause of this behavior is DNS inconsistency. During the host addition process, vCenter performs forward and reverse lookups to validate the host's identity.
• In this scenario, performing an nslookup from the vCenter Server to the ESXi host reveals two different FQDN (Fully Qualified Domain Name) entries associated with the same IP address.

Resolution

To resolve this issue, the stale or Duplicate DNS records must be mapped to ensure a 1:1 mapping between the Hostname, FQDN, and IP address. 

      Verify the Duplicate Entry and Clean up DNS Records 

1. Access your DNS Server (e.g. Windows DNS Manager).
2. Locate the Forward Lookup Zone and Reverse Lookup Zone for your management network.
3. Search for the ESXi host's IP and Name.
4. Remove the duplicate or stale FQDN entry.
5. Ensure only one record for the ESXI host exist there 
6. Try to Add the ESXI host back to the vCenter