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Central Administration Site (CAS)

The ConfigMgr Central Administration site (CAS) is the top site server in a configMgr Hierarchy. Nothing can be above him. Contrary to what a lot of people might think, a CAS is not mandatory to have, nor always needed. For a matter a fact, a CAS can be a pretty rare thing, and you might end up without never having to need a CAS in your ConfigMgr admin life.

The main reason why you will need a CAS in hierarchy is when you actually need a second primary site in hierarchy. That is actually to most important reason for adding a CAS in your ConfigMgr Infrastrucutre.

Key Infos

Feature Value
Number of clients (Max)
Can have Parent
 Can have Child

When do I need a CAS ?

When Do I want to install a CAS ?

  1. If you have more then 100 000 clients to manage.
  2. If you need to add a primary site to your hierarchy

Addind a CAS to your existing ConfigMgr Hierarchy

What are up’s and down’s

When to add a CAS to an existing ConfigMgr Infrastructure?

With ConfiMgr 2007, it was verry normal to have a big hierarchy, with a lot of components involved in it. ConfiMgr 2012 really changed on that matter, and it is possible to have the same amount of control with a hierarchy way less complicated to manage.

Adding a CAS, is one of these operations that could really make your hierarchy way more complicated that it actually needs to be, and it might not even give you so many benefits once it is there.

Adding a CAS, means to ‘extend an existing primary site’, and to make that primary child, the first child of your cas. There are also some hard limit that CAS can deal with. For instance, it supports only up 25 Primary sites. (Each of these supports up to 250 Secodary sites).

Ask yourself the right questions!

In order to decided whether or not adding a CAS to your existing ConfigMgr infrastrucutre, ask your self the following questions:

  1. Do you need a nother Primary site?
    1. If the answer is no the chances are that you are lucky, and that you don’t really need a CAS after all.

How Many clients?

Adding a CAS in your hierarchy, is one of the two reasons why you would want to add one. (implicite once, since adding a new primary site means adding a new CAS).

The following numbers highlight what a CAS really supports in term of clients:

Type Number
Desktops (Computers -> Windows, Linux,Unix) 700 000
MAC 25 000
Mobile device management (on prem) 100 000
Mobile device management (Cloud based with Intune) 300 000

Adding a CAS

Allowed site systems on a CAS:

The following table lists which Site systems you can install on a primary site:

Site system role Can be installed?
Application Catalog Web Service point False
Application Catalog website point False
Asset Intelligence synchronization point true
 Certificate registration point true
 Distribution point False
 Fall back status point False
 Management point False
 End point Protection point true
 Enrollment point False
 Enrollment proxy point False
Out of band service point False
Reporting services point true
Software update point true
State Migration Point False
system Health validator point true
Microsoft Intune connector true

Key take aways