SRV records play an important role in an Active Directory Domain. A DC can not function without it's Service Records. The following services or Windows Components use the SRV records:
- AD Replication
- When replicating information to other domain controllers. DSA always queries the domain controllers using SRV Query.
- Group Policy
- Winlogon Service pulls the list of GPOs from the domain controller. To find the domain controller it looks for SRV records in the domain zone.
- Client Authentication
- Client finds the domain controller with the help of DNS Server by querying DC's SRV record in the DNS Domain Zone.
- AD Management Tools
- Active Directory Users and Computers, Active Directory Domains and Trusts, Active Directory Sites and Services and other AD Tools always query the DNS server to find the domain controller.
- Group Policy Editor (Gpedit.msc)
- By default, Gpedit.msc uses the PDC to edit the Group Policy. It queries the DNS Server to find the IP Address of the PDC.
- Third-party applications
- Any third-party application query DNS to find the domain controller.
