Purpose: To understand how a Boundary and an Overlapping Boundary functions in SCCM 2012.
Understanding boundaries is fundamental to successfully operate Configuation Manager 2012. Everything that the product does towards workstations happens inside a selected boundary. With boundaries we point a workstatioon which distribution point to use when downloading programs, applications, windows updates, third party updates, virus definitions and such. Everything runs smoothly when you begin creating your boundaries until you create your first overlapping boundary.
The problem occurs when you define an IP RANGE to overlap another IP RANGE.
|BOUNDARY (ip address range)||“HQ Office”||10.201.0.4 – 10.201.255.254|
|BOUNDARY (ip address range)||“Seaside Office”||10.201.7.0 – 10.201.7.200|
And you create two BOUNDARY GROUPS and include these BOUNDARIES into different BOUNDARY GROUPS.
|BOUNDARY GROUP 1||“HQ Office”||Content Location 1|
|BOUNDARY GROUP 2||“Seaside Office”||Content Location 2|
In the situation above, the subnet (10.201.7.0 – 10.201.7.200) workstations will query SCCM for a BOUNDARY GROUP for themselves (and the Distribution Point assigned to the Boundary Group). The workstations inside the overlapping IP RANGE will receive two content locations: Content Location 1 and Content Location 2 (hence Distribution Point 1 and Distribution Point 2).
It is said in the offical documentation that the “closest” distribution point will be selected, but this is actually a random selection. Normally, this might not cause a problem if the internet connection speed does not vary. But in a case where a MOBILE DISTRIBUTION POINT has been delivered to a seaside office behind a slow ADSL connection, you will notice performance issues in a 10Gt operating system deployment.
Workstation LAB701 (10.220.45.234) is inside the following OVERLAPPING BOUNDARIES
Workstation LAB702 (10.220.45.235) is inside the following OVERLAPPING BOUNDARIES
|Mobile Distribution Point #1||(10.220.45.1 – 10.220.45.240)||physically in seaside office subnet, fast internet connection|
|DataCenter Distribution Point #1||(10.50.1.1 – 10.250.1.1)||physically in HQ office subnet, very slow internet connection to seaside office.|
Operating System Installation (LAB701)
We begin installing an operating system and observe where the source files are being downloaded from. In this example both of the distribution points were selected as a candidate for a download location. However, the first distribution point (Seaside Office) was selected randomly to be the download location and everything installed just fine under one hour.
Operating System Installation (LAB702)
We begin installing a operating system and observe where the source files are being downloaded from. In this example both of the distribution points were selected as a candidate for a download location. However, the second distribution point (HQ Office) was now selected randomly to be the download location and the operating system took eight hours to download before the installation could begin.
Never have overlapping boundaries, if your internet connection speed varies between the distribution points you are offering as available download locations.