Injustice - Developers Among Us (SciFiDevCon 2024)
Active Directory Features.pptx
1. Active Directory uses sites to:
Optimize replication for speed and bandwidth consumption between domain
controllers.
Locate the closest domain controller for client logon, services, and directory
searches.
Direct a Distributed File System (DFS) client to the server that is hosting the
requested data within the site.
2. Active Directory KCC Architecture and
Processes
The replication topology is generated by the Knowledge Consistency Checker
(KCC)
The KCC functions locally by reading, creating, and deleting Active Directory
data
KCC that runs on one domain controller does not communicate directly with
the KCC on any other domain controller..
3. Active Directory KCC Architecture and
Processes
The KCC communicates with other KCCs only to make a remote procedure call
(RPC) request for replication error information.
The KCC uses the error information to identify gaps in the replication
topology.
Note
The KCC uses only RPC to communicate with the directory service. The KCC
does not use Lightweight Directory Access Protocol (LDAP).
4. ISTG & KCC
One domain controller in each site is selected as the Intersite Topology
Generator (ISTG).
To enable replication across site links, the ISTG automatically selects one or
more bridgehead servers to perform site-to-site replication.
A bridgehead acts like a gateway for Site-To-Site Replication.
Thus, the scope of operation for the KCC is the local server only, and the
scope of operation for the ISTG is a single site.
5.
6. Control Replication Latency and Cost
Replication latency begins when a directory update occurs on an originating
domain controller and ends when replication of the change is received on the
last domain controller in the forest that requires the change.
A lower-cost route is preferred by the ISTG when generating the replication
topology.
7. Effect Client Affinity
Active Directory clients locate domain controllers according to their site
affiliation.
Domain controllers register SRV resource records in the DNS database that
map the domain controller to a site.
When a client requests a connection to a domain controller (for example,
when logging on to a domain computer), the domain controller Locator uses
the site SRV resource record to locate a domain controller with good
connectivity whenever possible.
Sites can also be used by certain applications, such as DFS, to ensure that
clients locate servers that are within the site or, if none is available, a server
in the next closest site.
8. Connection Objects
Ownership of Connection Objects
Connections that are created automatically by the KCC are “owned” by the KCC. If
you create a new connection manually, the connection is not owned by the KCC. If
a connection object is not owned by the KCC, the KCC does not modify it or delete
it.
If you use an LDAP editor such as Ldp.exe or Adsiedit.msc to change a connection
object property, the KCC reverses the change the next time it runs.
If you use Active Directory Sites and Services to change a connection object
property, the object is changed from automatic to manual and the KCC no longer
owns it.
If you create a new connection object that duplicates one that the KCC has
already created, your duplicate object is created and the KCC-created object is
deleted by the KCC the next time it runs.
9. NTDS Site Settings Object
The identity of the ISTG role owner for the site. The KCC on this domain
controller is responsible for identifying bridgehead servers.
Whether domain controllers in the site cache membership of universal groups
and the site in which to find a global catalog server for creating the cache.
The default schedule that applies to connection objects.
10. Replication Transports
There are three levels of connectivity for replication of Active Directory
information:
Uniform high-speed, synchronous RPC over IP within a site.
Point-to-point, synchronous, low-speed RPC over IP between sites.
Low-speed, asynchronous SMTP between sites. (For DC’s belonging to
different domain. Only Configuration, Schema and GC replication)
