Skip to main content

Active Directory SRV Records

 Active Directory SRV Records


What DNS entries (SRV Records) does Windows 2000/2003 add when you create a domain?

In order for Active Directory to function properly, DNS servers must provide support for Service Location (SRV) resource records described in RFC 2052, A DNS RR for specifying the location of services (DNS SRV). SRV resource records map the name of a service to the name of a server offering that service. Active Directory clients and domain controllers use SRV records to determine the IP addresses of domain controllers. Although not a technical requirement of Active Directory, it is highly recommended that DNS servers provide support for DNS dynamic updates described in RFC 2136, Observations on the use of Components of the Class A Address Space within the Internet.
The Windows 2000 DNS service provides support for both SRV records and dynamic updates. If a non-Windows 2000 DNS server is being used, verify that it at least supports the SRV resource record. If not, it must be upgraded to a version that does support the use of the SRV resource record. For example, Windows NT Server 4.0 DNS servers must be upgraded to Service Pack 4 or later to support SRV resource records. A DNS server that supports SRV records but does not support dynamic update must be updated with the contents of the Netlogon.dns file created by the Active Directory Installation wizard while promoting a Windows 2000 Server to a domain controller. The Netlogon.dns file is described in the following section.
So now you understand that Windows 2000 domains rely heavily on DNS entries. If you enable dynamic update on the relevant DNS zones, W2K creates these entries automatically:

  • _ldap._tcp.

Enables a client to locate a W2K domain controller in the domain named by . A client searching for a domain controller in the domain dpetri.net would query the DNS server for _ldap._tcp.dpetri.net.

  • _ldap._tcp.._sites.

Enables a client to find a W2K domain controller in the domain and site specified (e.g., _ldap._tcp.lab._sites.dpetri.net for a domain controller in the Lab site of dpetri.net).

  • _ldap._tcp.pdc._ms-dcs.

Enables a client to find the PDC flexible single master object (FSMO) role holder of a mixed-mode domain. Only the PDC of the domain registers this record.

  • _ldap._tcp.gc._msdcs.

Enables a client to find a Global Catalog (GC) server. Only domain controllers serving as GC servers for the tree will register this name. If a server ceases to be a GC server, the server will deregister the record.

  • _ldap._tcp. ._sites.gc._msdcs.

Enables a client to find a GC server in the specified site (e.g., _ldap._tcp.lab._sites.gc._msdcs.dpetri.net).

  • _ldap._tcp..domains._msdcs.

Enables a client to find a domain controller in a domain based on the domain controller’s globally unique ID. A GUID is a 128-bit (8 byte) number that generates automatically for referencing Active Directory objects.


Enables a client to find a domain controller through a normal Host record.

Comments

Post a Comment

Popular posts from this blog

Integration with vCloud Director failing after NSXT upgrade to 4.1.2.0 certificate expired

  Issue Clarification: after upgrade from 3.1.3 to 4.1.2.0 observed certificate to be expired related to various internal services.   Issue Verification: after Upgrade from 3.1.3 to 4.1.2.0 observed certificate to be expired related to various internal services.   Root Cause Identification: >>we confirmed the issue to be related to the below KB NSX alarms indicating certificates have expired or are expiring (94898)   Root Cause Justification:   There are two main factors that can contribute to this behaviour: NSX Managers have many certificates for internal services. In version NSX 3.2.1, Cluster Boot Manager (CBM) service certificates were incorrectly given a validity period of 825 days instead of 100 years. This was corrected to 100 years in NSX 3.2.3. However any environment originally installed on NSX 3.2.1 will have the internal CBM Corfu certs expire after 825 regardless of upgrade to the fixed version or not. On NSX-T 3.2.x interna...
Post a Comment
Read more

Calculate how much data can be transferred in 24 hours based on link speed in data center

  In case you are planning for migration via DIA or IPVPN link and as example you have 200Mb stable speed so you could calculate using the below formula. (( 200Mb /8)x60x60x24) /1024/1024 = 2TB /per day In case you have different speed you could replace the 200Mb by any rate to calculate as example below. (( 5 00Mb /8)x60x60x24) /1024/1024 =  5.15TB  /per day So approximate each 100Mb would allow around 1TB per day.
Post a Comment
Read more

Device expanded/shrank messages are reported in the VMkernel log for VMFS-5

    Symptoms A VMFS-5 datastore is no longer visible in vSphere 5 datastores view. A VMFS-5 datastore is no longer mounted in the vSphere 5 datastores view. In the  /var/log/vmkernel.log  file, you see an entry similar to: .. cpu1:44722)WARNING: LVM: 2884: [naa.6006048c7bc7febbf4db26ae0c3263cb:1] Device shrank (actual size 18424453 blocks, stored size 18424507 blocks) A VMFS-5 datastore is mounted in the vSphere 5 datastores view, but in the  /var/log/vmkernel.log  file you see an entry similar to: .. cpu0:44828)LVM: 2891: [naa.6006048c7bc7febbf4db26ae0c3263cb:1] Device expanded (actual size 18424506 blocks, stored size 18422953 blocks)   Purpose This article provides steps to correct the VMFS-5 partition table entry using  partedUtil . For more information see  Using the partedUtil command line utility on ESX and ESXi (1036609) .   Cause The device size discrepancy is caused by an incorrect ending sector for the VMFS-5 partition on the ...
Post a Comment
Read more