How can I find out the name/IP address of the AD domain controller on my network?
On any computer, that has DNS configured to use AD's DNS server do:
Start -> Run ->
set type=all _ldap._tcp.dc._msdcs.DOMAIN_NAME
Replace DOMAIN_NAME with the actual domain name e.g. example.com. Read more here.
For a computer that is a member of a domain the Environment Variable LOGONSERVER contains the name of the DC that authenticated the current user. This is obviously not going to be all DC's in a multi-DC environment but if all you want is a quick way to find the name of a Domain Controller then from a command shell:
set l <enter>
Will return all Environment variables that start with "L" including the name of a DC.
An unmentioned, super easy, and quick option is to run this from a command prompt:
Just replace 'domainname' with your domain
You can also run some other options to find out more:
/dcname:domainname gets the PDC name for the domain
/dsgetdc:domainname has flags for other information
nltest /? in your prompt to get more options! :)
From a command prompt, run
gpresult. You will get:
- General workstation and domain information
- For both the computer and the user:
- Distinguished name in AD and which DC the policy was applied from
- Applied Group Policy objects
- List of security groups a member of
Here is example output of running
gpresult. You can also specify
gpresult /z to get more detailed information.
DNS and DHCP are the best way to check since there can be Unix/Linux machines on the network managed by the AD domain controller or acting as the domain controller.
Plus, considering active directory is nothing more than Microsoft's version of Kerberos, LDAP, dhcp and dns. It would be better to understand and debug things at lower layers than layer 7+. This is because the operating system would preform these same requests and the underlining RFC for each protocol actually operates at a OSI level not the "insert favorite tool here" level.
Then using dns to check for the _kerberos._tcp, _kpasswd._tcp, _LDAP._TCP.dc._msdcs, and _ldap._tcp SRV records:
nslookup -type=srv _kerberos._tcp.EXMAPLE.COM nslookup -type=srv _kpasswd._tcp.EXAMPLE.COM nslookup -type=srv _ldap._tcp.EXAMPLE.COM nslookup -type=srv _ldap._tcp.dc._msdcs.EXAMPLE.COM .EXAMPLE.COM ::= value returned from dhcp option-1
This breaks down into three areas, two are protocol supported DNS-SD records:
_kpasswd._tcp(also under UNIX/Linux/OSX+some windows networks has
_kadmin._tcp) are for kerberos
_ldap._tcpis for ldap (openldap, opendc, sun/oracle directory, ms ad)
_LDAP._TCP.dc._msdcsis the Microsoft only extension to ldap to map the domain controller.
Just find DC names
nslookup -type=any %userdnsdomain%.
(Note: The trailing dot in "%userdnsdomain%." is on purpose. It stops your local nslookup from using any DNS search path strings.)
Find more AD related DNS domains
I whipped up a quick and dirty batch file, so that I don't have to remember the DNS domain names and/or have to type them all. (List may not be complete.)
Works from domain joined machines. If your machine is not domain joined, then you must manually set USERDNSDOMAIN to what you want.
@setlocal @REM Test AD DNS domains for presence. @REM For details see: http://serverfault.com/a/811622/253701 nslookup -type=srv _kerberos._tcp.%userdnsdomain%. nslookup -type=srv _kerberos._udp.%userdnsdomain%. @echo . nslookup -type=srv _kpasswd._tcp.%userdnsdomain%. nslookup -type=srv _kpasswd._udp.%userdnsdomain%. @echo . nslookup -type=srv _ldap._tcp.%userdnsdomain%. @echo . nslookup -type=srv _ldap._tcp.dc._msdcs.%userdnsdomain%. @echo . nslookup -type=srv _ldap._tcp.pdc._msdcs.%userdnsdomain%. @echo . @REM Those next few lines here are forest specific: @REM Change the next line your current domain is not also the forest root. @SET "DNSFORESTNAME=%USERDNSDOMAIN%" nslookup -type=srv _ldap._tcp.gc._msdcs.%DNSFORESTNAME%. @echo . nslookup -type=srv _gc._tcp.%DNSFORESTNAME%.
TestAdDnsRecords.cmd | more. There is a lot of text output.
- MSDN "ServerGeeks" blog, 2014-07-12, Habibar Rahman, DNS Records that are required for proper functionality of Active Directory (Archived here.)
- TechNet, Resource Kits > Distributed Systems Guide > Desktop Configuration Management > Active Directory > Name Resolution in Active Directory > Locating Active Directory Servers > SRV Resource Records (Archived here.)