When a Spine-Leaf topology adopts the Intermediate System to Intermediate System (IS-IS) routing protocol, the Leaf node receives Link State Packets (LSPs) from all the other nodes thus having the entire routing information of the topology. This is usually considered unnecessary and costly. This document describes a solution to this problem by assigning different area identifiers (AIDs) to the Leaf nodes. The solution requires that an IS-IS router SHOULD check a Level-1 LSP's AIDs before it advertises the LSP to its neighbor.