Monitor Active Directory
The Active Directory (AD) database, also known as the NT Directory Service (NTDS) database, is the central repository for user, computer, network, device, and security objects in a Windows AD domain or forest. You can use Splunk Enterprise to record changes to AD, such as the addition or removal of a user, host, or domain controller (DC).
If you use Splunk Cloud Platform, you must use the Splunk Universal forwarder to collect Active Directory data from a Windows domain controller or member machine and forward that data to Splunk Cloud Platform. On Splunk Enterprise, you can also use the universal forwarder, or you can Install Splunk Enterprise directly onto a Windows machine and collect the AD data that way.
You can configure AD monitoring to watch for changes to your Active Directory forest and collect user and machine metadata. You can use this feature combined with dynamic list lookups to decorate or modify events with any information available in AD. See About lookups in the Knowledge Manager Manual.
After you configure Splunk Enterprise to monitor your Active Directory, it takes a baseline snapshot of the AD schema. It uses this snapshot to establish a starting point for monitoring.
The AD monitoring input runs as a separate process called
splunk-admon.exe. It runs once for every Active Directory monitoring input you define in Splunk Enterprise.
Reasons to monitor Active Directory
If you maintain the integrity, security, and health of your Active Directory, then what happens with it day to day is a concern. With Splunk Enterprise, you can monitor what and when things changed in your AD and who changed them.
You can transform this data into reports for corporate security compliance or forensics, for example. You can also use the data retrieved for intrusion alerts for immediate response. Additionally, you can create health reports with the data indexed for future AD infrastructure planning activities, such as assignment of operations master roles, AD replicas, and global catalogs across DCs.
You must meet the following requirements to monitor an Active Directory schema:
- Splunk Enterprise must run on Windows. See Install on Windows in the Installation Manual.
- Splunk Enterprise must run as a domain user. See Choose the Windows user Splunk Enterprise should run as in the Installation Manual.
- The user Splunk Enterprise runs as must have read access to all AD objects that you want to monitor.
Technical considerations for monitoring Active Directory
For best results with monitoring AD, note the following considerations:
- The AD monitor is only available on the Splunk platform on Windows. Splunk Cloud Platform cannot monitor AD directly.
- While you cannot monitor AD changes from a *nix version of Splunk Enterprise, you can forward AD data from a Windows version of Splunk Enterprise or the universal forwarder to a *nix indexer.
- The AD monitoring process can run under a full instance or on any kind of forwarder.
- The host that monitors changes to AD must belong to the domain or forest you want to monitor.
- The user that Splunk Enterprise runs as must also be part of the domain.
- The permissions that the user has determine which parts of AD Splunk can monitor.
For information on deciding which user Splunk Enterprise runs as at installation time, see Choose the Windows user Splunk Enterprise should run as in the Installation Manual.
How the AD monitor interacts with AD
When you set up an AD monitoring input, the input connects to an AD domain controller to authenticate and, if necessary, performs any security ID (SID) translations while it gathers the AD schema or changes events.
The AD monitor uses the following logic to interact with Active Directory after you set it up:
- If you specify a domain controller when you define the input, then the input uses that domain controller for AD operations. You can specify a domain controller either with the
targetDcsetting in inputs.conf or the
Target domain controllerfield in Splunk Web.
- If you do not specify a domain controller, then the input does the following:
- The input attempts to use the local system cache to authenticate or resolve SIDs.
- If the monitor cannot authenticate or resolve SIDs that way, it attempts a connection to the domain controller that the machine that runs the input used to log on.
- If that does not work, then the input attempts to use the closest AD domain controller that has a copy of the Global Catalog.
- If the domain controller that you specify is not valid or a domain controller cannot be found, then the input generates an error message.
The AD monitor does not chase LDAP referrals
If the AD monitor makes a Lightweight Directory Access Protocol (LDAP) query and receives a referral, it does not chase this referral to complete the query. An LDAP referral represents a problem with your LDAP configuration and you or your designated administrators must determine and fix the configuration problem within AD.
Configure Active Directory monitoring with configuration files
You can configure AD monitoring either in Splunk Web or by editing configuration files. You can access more options, such as the ability to configure monitors for multiple DCs, when using configuration files.
The inputs.conf configuration file controls Active Directory monitoring configurations. Edit copies of inputs.conf in the %SPLUNK_HOME%\etc\system\local directory. If you edit them in the default directory, an upgrade overwrites your changes. For more information about configuration file precedence, see Configuration file precedence.
- Open %SPLUNK_HOME%\etc\system\local\inputs.conf for editing. Create this file if it does not exist.
- Add the appropriate AD monitoring stanzas and settings.
By default, when you enable AD monitoring inputs, Splunk Enterprise gathers AD change data from the first domain controller that it can attach to. If that is acceptable, no further configuration is necessary.
inputs.conf contains one stanza for each AD monitoring input, with a header like the following:
[admon://<name of stanza>]
In each stanza, you can specify the following settings:
||Yes||The unique name of the domain controller you want to use for AD monitoring.
Specify a unique name for this setting if the following circumstances apply:
To target multiple DCs, add another
|the local host|
||No||A fully qualified Lightweight Directory Access Protocol (LDAP) name (for example:
The value of
|The highest root domain in the tree that Splunk Enterprise can access|
||No||How much of the target AD container to index. A value of 0 means to index only the target container, and not traverse into subcontainers within that container. A value of 1 means to enumerate all sub-containers and domains that it has access to.||1 (monitor all domains that Splunk Enterprise has access to)|
||No||Whether or not the input enumerates all existing available AD objects when it first runs. A value of 0 means not to set a baseline. A value of 1 means to set a baseline.||1 (set the baseline)|
||No||The index to route AD monitoring data to.||the |
||No||Whether or not Splunk Enterprise runs the input. A value of 0 means that the input is enabled, and a value of 1 means that the input is disabled.||1 (disabled)|
Example AD monitoring configurations
The following are examples of how to use the inputs.conf file to monitor desired portions of your AD network.
See the following example to index data from the top of the AD directory:
#Gather all AD data that this server can see [admon://NearestDC] targetDc = startingNode =
See the following example to use a DC that is at a higher root level than an OU you want to target for monitoring:
# Use the pri01.eng.ad.splunk.com domain controller to get all AD metadata for # the Computers OU in this forest. We want schema data for the entire AD tree, not # just this node. [admon://DefaultTargetDc] targetDc = pri01.eng.ad.splunk.com startingNode = OU=Computers,DC=eng,DC=ad,DC=splunk,DC=com
See the following example to monitor multiple domain controllers:
# Get change data from two domain controllers (pri01 and pri02) in the same AD tree. # Index both and compare/contrast to ensure AD replication is occurring properly. [admon://DefaultTargetDc] targetDc = pri01.eng.ad.splunk.com startingNode = OU=Computers,DC=eng,DC=ad,DC=splunk,DC=com [admon://SecondTargetDc] targetDc = pri02.eng.ad.splunk.com startingNode = OU=Computers,DC=eng,DC=ad,DC=splunk,DC=com
Sample AD monitoring output
When the AD monitoring utility runs, it gathers AD change events, which the Splunk platform then indexes. To view these events as they arrive, use the Search & Reporting app.
There are several types of AD change events that the Splunk platform can index. Examples of these events follow. Some of the content of these events is obscured or altered for publication purposes.
When an AD object changes, the Splunk platform generates an update event. The software logs this change as type
2/1/10 3:17:18.009 PM 02/01/2010 15:17:18.0099 dcName=stuff.splunk.com admonEventType=Update Names: objectCategory=CN=Computer,CN=Schema,CN=Configuration name=stuff2 displayName=stuff2 distinguishedName=CN=stuff2,CN=Computers Object Details: sAMAccountType=805306369 sAMAccountName=stuff2 logonCount=4216 accountExpires=9223372036854775807 objectSid=S-1-5-21-3436176729-1841096389-3700143990-1190 primaryGroupID=515 pwdLastSet=06:30:13 pm, Sat 11/27/2010 lastLogon=06:19:43 am, Sun 11/28/2010 lastLogoff=0 badPasswordTime=0 countryCode=0 codePage=0 badPwdCount=0 userAccountControl=4096 objectGUID=blah whenChanged=01:02.11 am, Thu 01/28/2010 whenCreated=05:29.50 pm, Tue 11/25/2008 objectClass=top|person|organizationalPerson|user|computer Event Details: uSNChanged=2921916 uSNCreated=1679623 instanceType=4 Additional Details: isCriticalSystemObject=FALSE servicePrincipalName=TERMSRV/stuff2|TERMSRV blah dNSHostName=stuff2.splunk.com operatingSystemServicePack=Service Pack 2 operatingSystemVersion=6.0 (6002) operatingSystem=Windows Vista? Ultimate localPolicyFlags=0
When an AD object has been marked for deletion, the Splunk platform generates a delete event. The event type is similar to
admonEventType=Update, except that it contains the
isDeleted=True key/value pair at the end of the event.
2/1/10 3:11:16.095 PM 02/01/2010 15:11:16.0954 dcName=stuff.splunk.com admonEventType=Update Names: name=SplunkTest DEL:blah distinguishedName=OU=SplunkTest\0ADEL:blah,CN=Deleted Objects DEL:blah Object Details: objectGUID=blah whenChanged=11:31.13 pm, Thu 01/28/2010 whenCreated=11:27.12 pm, Thu 01/28/2010 objectClass=top|organizationalUnit Event Details: uSNChanged=2922895 uSNCreated=2922846 instanceType=4 Additional Details: dSCorePropagationData=20100128233113.0Z|20100128233113.0Z|20100128233113.0Z|16010108151056.0Z lastKnownParent=stuff '''isDeleted=TRUE'''
When AD monitoring inputs are configured, the Splunk platform tries to capture a baseline of AD metadata when it starts. the Splunk platform generates event type
admonEventType=Sync, which represents the instance of one AD object and all its field values. the Splunk platform tries to capture all of the objects from the last recorded Update Sequence Number (USN).
When you restart Splunk Enterprise or the
splunk-admon.exe process, the software logs an extra
sync event. This is normal.
2/1/10 3:11:09.074 PM 02/01/2010 15:11:09.0748 dcName=ftw.ad.splunk.com admonEventType=Sync Names: name=NTDS Settings distinguishedName=CN=NTDS Settings,CN=stuff,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration cn=NTDS Settings objectCategory=CN=NTDS-DSA,CN=Schema,CN=Configuration,DC=ad,DC=splunk,DC=com fullPath=LDAP://stuff.splunk.com/<GUID=bla bla bla> CN=NTDS Settings Object Details: whenCreated=10:15.04 pm, Tue 02/12/2008 whenChanged=10:23.00 pm, Tue 02/12/2008 objectGUID=bla bla bla objectClass=top|applicationSettings|nTDSDSA classPath=nTDSDSA Event Details: instanceType=4 Additional Details: systemFlags=33554432 showInAdvancedViewOnly=TRUE serverReferenceBL=CN=stuff,CN=Domain System Volume (SYSVOL share),CN=File Replication Service,CN=System options=1 msDS-hasMasterNCs=DC=ForestDnsZones|DC=DomainDnsZones|CN=Schema,CN=Configuration|CN=Configuration msDS-HasInstantiatedNCs= msDS-HasDomainNCs=blah msDS-Behavior-Version=2 invocationId=bla bla bla hasMasterNCs=CN=Schema,CN=Configuration|CN=Configuration dSCorePropagationData= dMDLocation=CN=Schema,CN=Configuration nTSecurityDescriptor=NT AUTHORITY\Authenticated Users SchemaName=LDAP://stuff.splunk.com/schema/nTDSDSA
When you restart Splunk Enterprise after configuring it for AD monitoring, it generates a schema type event:
admonEventType=schema. This event shows the definitions of every object in the Active Directory structure. The
optional fields are listed for each AD object. Failure to see all of these fields can indicate a problem with Active Directory.
02/01/2010 15:11:16.0518 dcName=LDAP://stuff.splunk.com/ admonEventType=schema className=msExchProtocolCfgSMTPIPAddress classCN=ms-Exch-Protocol-Cfg-SMTP-IP-Address instanceType=MandatoryProperties nTSecurityDescriptor=MandatoryProperties objectCategory=MandatoryProperties objectClass=MandatoryProperties adminDescription=OptionalProperties adminDisplayName=OptionalProperties allowedAttributes=OptionalProperties allowedAttributesEffective=OptionalProperties allowedChildClasses=OptionalProperties allowedChildClassesEffective=OptionalProperties bridgeheadServerListBL=OptionalProperties canonicalName=OptionalProperties cn=OptionalProperties createTimeStamp=OptionalProperties description=OptionalProperties directReports=OptionalProperties displayName=OptionalProperties displayNamePrintable=OptionalProperties distinguishedName=OptionalProperties dSASignature=OptionalProperties dSCorePropagationData=OptionalProperties extensionName=OptionalProperties flags=OptionalProperties fromEntry=OptionalProperties frsComputerReferenceBL=OptionalProperties fRSMemberReferenceBL=OptionalProperties fSMORoleOwner=OptionalProperties heuristics=OptionalProperties isCriticalSystemObject=OptionalProperties isDeleted=OptionalProperties isPrivilegeHolder=OptionalProperties lastKnownParent=OptionalProperties legacyExchangeDN=OptionalProperties managedObjects=OptionalProperties masteredBy=OptionalProperties memberOf=OptionalProperties modifyTimeStamp=OptionalProperties mS-DS-ConsistencyChildCount=OptionalProperties mS-DS-ConsistencyGuid=OptionalProperties msCOM-PartitionSetLink=OptionalProperties msCOM-UserLink=OptionalProperties msDFSR-ComputerReferenceBL=OptionalProperties msDFSR-MemberReferenceBL=OptionalProperties msDS-Approx-Immed-Subordinates=OptionalProperties msDs-masteredBy=OptionalProperties msDS-MembersForAzRoleBL=OptionalProperties msDS-NCReplCursors=OptionalProperties msDS-NCReplInboundNeighbors=OptionalProperties msDS-NCReplOutboundNeighbors=OptionalProperties msDS-NonMembersBL=OptionalProperties msDS-ObjectReferenceBL=OptionalProperties msDS-OperationsForAzRoleBL=OptionalProperties msDS-OperationsForAzTaskBL=OptionalProperties msDS-ReplAttributeMetaData=OptionalProperties msDS-ReplValueMetaData=OptionalProperties msDS-TasksForAzRoleBL=OptionalProperties msDS-TasksForAzTaskBL=OptionalProperties msExchADCGlobalNames=OptionalProperties msExchALObjectVersion=OptionalProperties msExchHideFromAddressLists=OptionalProperties msExchInconsistentState=OptionalProperties msExchIPAddress=OptionalProperties msExchTurfList=OptionalProperties msExchUnmergedAttsPt=OptionalProperties msExchVersion=OptionalProperties msSFU30PosixMemberOf=OptionalProperties name=OptionalProperties netbootSCPBL=OptionalProperties nonSecurityMemberBL=OptionalProperties objectGUID=OptionalProperties objectVersion=OptionalProperties otherWellKnownObjects=OptionalProperties ownerBL=OptionalProperties partialAttributeDeletionList=OptionalProperties partialAttributeSet=OptionalProperties possibleInferiors=OptionalProperties proxiedObjectName=OptionalProperties proxyAddresses=OptionalProperties queryPolicyBL=OptionalProperties replicatedObjectVersion=OptionalProperties replicationSignature=OptionalProperties replPropertyMetaData=OptionalProperties replUpToDateVector=OptionalProperties repsFrom=OptionalProperties repsTo=OptionalProperties revision=OptionalProperties sDRightsEffective=OptionalProperties serverReferenceBL=OptionalProperties showInAddressBook=OptionalProperties showInAdvancedViewOnly=OptionalProperties siteObjectBL=OptionalProperties structuralObjectClass=OptionalProperties subRefs=OptionalProperties subSchemaSubEntry=OptionalProperties systemFlags=OptionalProperties unmergedAtts=OptionalProperties url=OptionalProperties uSNChanged=OptionalProperties uSNCreated=OptionalProperties uSNDSALastObjRemoved=OptionalProperties USNIntersite=OptionalProperties uSNLastObjRem=OptionalProperties uSNSource=OptionalProperties wbemPath=OptionalProperties wellKnownObjects=OptionalProperties whenChanged=OptionalProperties whenCreated=OptionalProperties wWWHomePage=OptionalProperties
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This documentation applies to the following versions of Splunk Cloud Platform™: 8.2.2112, 8.2.2201, 8.2.2202, 8.2.2203, 9.0.2205, 9.0.2208, 9.0.2209 (latest FedRAMP release), 9.0.2303
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