SCCM Site Boundary Types and its Advantages and Disadvantages

Boundaries for System Center Configuration Manager define network locations on your intranet that can contain devices that you want to manage. Boundary groups are logical groups of boundaries that you configure.

Types of Boundary's in SCCM.

• IP Subnet
• Active Directory Site
• IPv6 Prefix
• IP Range

Clients on the intranet evaluate their current network location and then use that information to identify boundary groups to which they belong.

Clients use boundary groups to:

• Find an assigned site: Boundary groups enable clients to find a primary site for client assignment (automatic site assignment).
• Find certain site system roles they can use: When you associate a boundary group with certain site system roles, the boundary group provides clients that list of site systems for use during content location and as preferred management points.

Clients that are on the Internet or configured as Internet-only clients do not use boundary information. These clients cannot use automatic site assignment and can always download content from any distribution point from their assigned site when the distribution point is configured to allow client connections from the Internet.

Best practices for boundaries and boundary groups:

• Use a mix of the fewest boundaries that meet your needs
• Avoid overlapping boundaries for automatic site assignment

Refer below MS links for more info:

https://docs.microsoft.com/en-us/sccm/core/servers/deploy/configure/boundaries

Site Boundary Type	Advantage	Disadvantage
IP Subnets	Using IP subnets to define the boundaries of Configuration Manager sites allows you to be very specific about which clients will be assigned to which Configuration Manager 2007 sites based on their individual subnets. This also allows you to assign computers residing in the same Active Directory sites, but on different subnets, to different Configuration Manager sites. NOTE: When adding IP subnets as boundaries for a site, you should ensure that the IP subnet being added as a boundary has not been added to an existing Active Directory site defined as a boundary for a different Configuration Manager site.	Each IP subnet you want to be part of your Configuration Manager boundaries must be entered individually in the Configuration Manager console. IP subnet changes or additions will require additional Configuration Manager boundary administration.
Active Directory Sites	Because Active Directory sites are based on physical network segments, the easiest method of defining Configuration Manager boundaries is to base them on Active Directory sites. This allows Configuration Manager administrators to split up or combine IP subnet boundaries based on logical, not physical, criteria. One advantage to using Active Directory sites as Configuration Manager boundaries is that subnet changes to Active Directory sites are automatically reflected within Active Directory boundaries. NOTE:Active Directory discovery methods can only be used to discover computers located within the boundaries defined by Active Directory site names.	Before assigning clients using Active Directory sites, you must ensure that the Active Directory administrators have included all of the subnets you expect to be present in the Active Directory site. If the Active Directory sites are not properly configured, and you use them for Configuration Manager boundaries, you will have unmanaged clients on those subnets.
IPv6 Prefix	IPv6 allows for many more addresses to be assigned and many current and future operating system releases will support its use.	IPv4-only systems cannot communicate directly with IPv6 computers and may require IP translation, such as NAT, to communicate.
IP Ranges	In some cases, you may not want to add an entire IP subnet as a boundary. In these cases it may be advantageous to specify only an IP range to use for client site assignment.	Entering IP ranges can result in more planning to ensure that the IP ranges used are not configured as part of an IP subnet boundary for a different Configuration Manager site.