ESXi host in "Not Responding" state due to Active Directory connectivity issues (0x9cb9: The domain is offline)

Products

• VMware vSphere ESXi

Issue/Introduction

• ESXi host shows as "Not Responding" or "Disconnected" in vCenter Server.
• Virtual Machines on the host remain powered on and accessible, but management via vCenter is lost.
• The hostd management agent may become unresponsive or crash.
• Restarting management agents via SSH or DCUI temporarily restores connectivity, but the host returns to a "Not Responding" state after several hours.
• The following error messages appear in /var/run/log/hostd.log: error hostd[ID] [Originator@6876 sub=Default] DJGetComputerDN: 0x9cb9: The domain is offline
• The following warnings may appear in /var/run/log/syslog.log: lwsmd[ID]: [netlogon] Found DC [DC_NAME] where LDAP port 389 is not accessible.

Environment

• ESXi 7.x
• ESXi 8.x

Cause

The ESXi host is joined to an Active Directory domain, but the Likewise (lwsmd) service cannot communicate with the Domain Controllers. This is often caused by network connectivity issues on LDAP port 389, stale domain entries on the host, or a password mismatch between the host and AD. When lwsmd fails to reach the domain, it can cause the hostd agent to hang while waiting for a response, leading to the "Not Responding" status.

Resolution

1. Verify Network Connectivity: Ensure the ESXi host can reach the Domain Controller on TCP/UDP port 389
2. Clear Stale Domain Entries
   
   • Access the Likewise registry shell:
     /usr/lib/vmware/likewise/bin/lwregshell
cd HKEY_THIS_MACHINE\services\lsass\parameters\providers\ActiveDirectory\DomainJoin
   • Delete entries
     delete_tree DOMAINNAME.COM
delete_value Default
   • Delete entry DomainJoin
     delete_tree DomainJoin
   • Restart Likewise
     /etc/init.d/lwsmd restart
3. Rejoin the Domain

• • Place the host in maintenance mode

• • Leave the domain
    /usr/lib/vmware/likewise/bin/domainjoin-cli leave
  • Join the domain again with valid credentials
    /usr/lib/vmware/likewise/bin/domainjoin-cli join [DomainName] [User] [Password]

Additional Information

Troubleshooting an ESXi host in a "not responding"/"disconnected" state