Quick Answer

The answer is that summarizing routes with CIDR for advertisement is the final step in the IP subnetting design process. This is correct because the logical order of subnetting design moves from broad requirements to specific allocation, then back to aggregation; after you have gathered network requirements, chosen a private address space, applied subnetting to create subnets, and assigned those subnets to specific segments, the last action is to summarize the resulting routes using CIDR to reduce the size of the routing table for efficient advertisement. On the ENCOR 350-401 exam, this drag-and-drop question tests your understanding of the full design lifecycle, and a common trap is placing summarization before subnet assignment—remember that you cannot summarize routes until you know which subnets are actually in use. A helpful memory tip is to think “Requirements, Space, Subnets, Assign, Summarize”—or simply the acronym “RSSAS” to lock in the correct order from first to last.