Unable to register with Compute Manager while installing VCF

Products

• VMware NSX

Issue/Introduction

• When NSX Manager tried to register the vCenter as Compute Manager, it fails with error similar to below.
  "DNS configuration for FQDN: nsx-manager.corp.local is incorrect. Please fix DNS configuration and retry Resolve workflow."
• On SDDC manager, you see logs similar to below.
  Unable to configure fabric for vcsa.corp.local on nsx-manager.corp.local. Remediation: Please check if vCenter is up and running also check if NSX Extension present in vCenter Server and delete the same. Retry the failed workflow. Reference Token: RXXXX4
• /var/log/cm-inventory/cm-inventory.log on NSX manager shows logs similar to below
  2026-01-16T06:02:04.754Z  INFO task-executor-1-2 CmInventoryService 79583 FABRIC [nsx@4413 comp="nsx-manager" level="INFO" subcomp="cm-inventory"] dig command output is []

Environment

VMware NSX on VCF

Cause

CM inventory uses dig for DNS lookup and reverse lookup. If the configured DNS server doesn't support dig, the name resolution will fail even if nslookup works leading to compute manager registration failure.

Resolution

Make sure the configured DNS server supports dig.

From NSX Manager CLI, it is expected that the following dig commands work.
[email protected]:~# dig nsx-manager.corp.local A +short
[email protected]:~# dig -x  1x.x.x.21

Additional Information

If DNS server replies to dig queries from NSX manager only when +nocookie is specified(e.g., dig +nocookie yourdomain.com), it suggests that the DNS server doesn't support cookie which is sent by the NSX manager by default. This is typical of old DNS servers and a FORMERR(format error) is sent back by the DNS server and the name resolution fails.