This is for a recent migration from SBS 2011 to Server 2016 Standard:
Following the Migration Guide everything seemed to go as expected but now several weeks after I realize the old SBS 2011 server is still showing as a domain controller. The server has been disconnected from the network so at this point I'm not sure what needs to be done to correct the problem
That is not possible if you have demoted the old SBS 2011. Why do you think it is still a DC? Can you run from an elevated Powershell prompt:
(Get-ADForest).Domains | %{ Get-ADDomainController -Filter * -Server $_ }
Copy the output in your answer.
PS C:\Windows\system32> (Get-ADForest).Domains | %{ Get-ADDomainController -Filter * -Server $_ }
****OLD SERVER****
ComputerObjectDN : CN=MG***-01,OU=Domain Controllers,DC=m***tys,DC=local
DefaultPartition : DC=m***tys,DC=local
Domain : m***tys.local
Enabled : True
Forest : m***tys.local
HostName : MG***-01.m***tys.local
InvocationId : fe546beb-0898-49dd-b7b8-797f46118c6d
IPv4Address :
IPv6Address :
IsGlobalCatalog : True
IsReadOnly : False
LdapPort : 389
Name : MG***-01
NTDSSettingsObjectDN : CN=NTDS Settings,CN=MG***-01,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=m***tys,DC=local
OperatingSystem : Windows® Small Business Server 2011 Standard
OperatingSystemHotfix :
OperatingSystemServicePack : Service Pack 1
OperatingSystemVersion : 6.1 (7601)
OperationMasterRoles : {}
Partitions : {DC=ForestDnsZones,DC=m***tys,DC=local, DC=DomainDnsZones,DC=m***tys,DC=local,
CN=Schema,CN=Configuration,DC=m***tys,DC=local,
CN=Configuration,DC=m***tys,DC=local...}
ServerObjectDN : CN=MG***-01,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=m***tys,DC=local
ServerObjectGuid : a0f10b5e-0548-4403-95e3-d1c53ab2efe6
Site : Default-First-Site-Name
SslPort : 636
****NEW SERVER****
ComputerObjectDN : CN=MG***-20,OU=Domain Controllers,DC=m***tys,DC=local
HostName : MG***-20.m***tys.local
InvocationId : adcfad44-c00e-4b2f-9b64-2ea774dcc037
IPv4Address : 192.168.16.88
IPv6Address : ::1
Name : MG***-20
NTDSSettingsObjectDN : CN=NTDS Settings,CN=MG***-20,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=m***tys,DC=local
OperatingSystem : Windows Server 2016 Standard
OperatingSystemServicePack :
OperatingSystemVersion : 10.0 (14393)
OperationMasterRoles : {SchemaMaster, DomainNamingMaster, PDCEmulator, RIDMaster...}
ServerObjectDN : CN=MG***-20,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=m***tys,DC=local
ServerObjectGuid : 2dc3ad58-5362-4f17-b82c-ca62aa54b421
You have done something wrong. The old SBS is not demoted at all or failed to demote. I will contact you offline and arrange a Teams session to help you this
let me know what info you need from me thanks
I have send you an email and we will take this offline.