What is Domain Controller Discovery?

Applies to

ONTAP 9.3+

Answer

• Domain Controller (DC) Discovery is an automatic procedure triggered by the Security Daemon (SecD) to identify which services are available to ONTAP.
  • It discovers all the DC's, including preferred DC's,  DC's in the local site, and all remote sites.
  • For later versions of ONTAP, DC Discovery also occurs for all known trusted Domains.
    • Contact Microsoft for more information on using Active Directory Sites and Services to manage sites to control what servers are discovered
• ONTAP determines the optimal DC to authenticate new CIFS connections against.
  • If there are many DC's in the environment, this can take some time.
  • As a result, accessing or enumerating shares during discovery can be noticeably slow depending on the environment.
  • The discovery process will be executed automatically (without being specifically triggered by the user) in 3 scenarios:
    • Joining the SVM's CIFS server to a domain
    • Periodic discovery is performed at an ~4 hour interval, to check for possible changes on the server or LIF configuration
    • Change of Preferred DC's
• Use the cifs domain discovered-servers commands to view and reset DC's

cluster1::> vserver cifs domain discovered-servers show

Node: node1
Vserver: vs1

Domain Name     Type     Preference DC-Name     DC-Address    Status
--------------- -------- ---------- ----------- ------------- -------
example.com     MS-LDAP  adequate   DC-1        1.1.3.4       OK
example.com     MS-LDAP  adequate   DC-2        1.1.3.5       OK
example.com     MS-DC    adequate   DC-1        1.1.3.4       OK
example.com     MS-DC    adequate   DC-2        1.1.3.5       OK

Additional Information

• Managing domain controller discovery
• How to discover Active Directory Domain Controllers using nslookup
• Add preferred domain controllers