What is Disjoint Namespace?
Typically, when using Microsoft Active Directory you use AD-integrated DNS and your AD domain name matches you DNS domain name, but you don’t have to. This is quite rare, but I’ve seen cases where the two don’t match. For example, you might have a Linux-based DNS, where you register an esx01.example.com DNS record for your ESXi host and then you join it to an Active Directory domain called corp.local.
That’s called a disjoint namespace. You can read this Microsoft article if you want to know more details: Disjoint Namespace.
In my personal opinion, using a disjoint namespace is asking for trouble, but it will still work if you really want to use it.
Problem
If you end up going down that route, there’s one caveat you should be aware of. When you joining a machine to AD, among other things, it needs to populate DNS name field property of the AD computer object. This is an example of ESXi computer object in Active Directory Users and Computers snap-in:
If you configure example.com domain in your ESXi Default TCP/IP stack, like so:
And then you try to, for example, join your ESXi host to corp.local AD domain, it will attempt to use esx-01a.example.com for computer object DNS name field. If you’re using a domain account with privileges restricted only to domain join, this operation will fail.
This is how the problem manifested itself in my case in ESXi host logs:
Failed to run provider specific request (request code = 8, provider = ‘lsa-activedirectory-provider’) -> error = 40315, symbol = LW_ERROR_LDAP_CONSTRAINT_VIOLATION, client pid = 2099303
If you’re using host profiles to join ESXi host to the domain, remediation will fail and you will see the following in /var/log/syslog.log:
WARNING: Domain join failed; retry count 1.
WARNING: Domain join failed; retry count 2.
Likewise (ActiveDirectory) Domain Join operation failed while joining new domain via username and password..
Note: this problem is specific to joining domain using a restricted service account. If you use domain administrator account, it will force the controller to add the computer object with a DNS name, which doesn’t match the AD name.
Solution
Make sure ESXi domain name setting matches the Active Directory domain name, not DNS domain name. You can still use the esx-01a.example.com record to add the ESXi hosts to vCenter, but you have to specify corp.local domain in DNS settings (or leave it blank), because this is what is going to be used to add the host to AD, like so:
This way your domain controller will be happy and ESXi host will successfully join the domain.
Additional Notes
While troubleshooting this issue I saw a few errors in ESXi host logs, which were a distraction, ignore them, as they don’t constitute an error.
This just means that the ESXi host Active Directory service is running, but host is not joined to a domain yet:
lsass: Failed to run provider specific request (request code = 12, provider = ‘lsa-activedirectory-provider’) -> error = 2692, symbol = NERR_SetupNotJoined, client pid = 2111366
IPC is inter-process communication. Likewise consists of multiple services that talk to each other. They open and close connections, this is normal:
lsass-ipc: (assoc:0x8ed7e40) Dropping: Connection closed by peer
I also found this command to be useful for deeper packet inspection between an ESXi host and AD domain controllers:
tcpdump-uw -i vmk0 not port 22 and not arp
References
- Joining vCenter Server Appliance or ESXi host into Active Directory domain fails with error: LW_ERROR_LDAP_CONSTRAINT_VIOLATION or LW_ERROR_LDAP_INSUFFICIENT_ACCESS (52929)
- Enabling logging for Likewise agents on ESXi/ESX (1026554)
- ESXI AND LIKEWISE – TROUBLESHOOTING GUIDE – PART 1
- ESXI AND LIKEWISE – TROUBLESHOOTING GUIDE – PART 2
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