A Loop-Free Alternate Shortest Path First (LFA SPF) policy allows the user to apply specific criteria, such as admin group and SRLG constraints, to the selection of a LFA backup next-hop for a subset of prefixes that resolve to a specific primary next-hop. See more details in the section titled ‟Loop-Free Alternate Shortest Path First (LFA SPF) Policies” in the Routing Protocols Guide.