I have reviewed this document as part of the Operational directorate's ongoing effort to review all IETF documents being processed by the IESG. These comments were written primarily for the benefit of the operational area directors. Document editors and WG chairs should treat these comments just like any other last call comments. Not being an expert in LFA, the review focus was only on operation. And, due to the density and specialization of the I-D, I would like to ask the authors whether they read RFC 5706 about 'ops and mgmt guidelines', i.e., to check whether this I-D considered migration from an existing LFA to the new one, interoperations with previous LFA and how correct operations can be verified. As the core topic is about loop-free alternates, we can assume that fault management and operations are at the core of this I-D. But, I encourage the authors to quickly review their document with RFC 5706 in mind. There are also some nits and typos such as " uitilized" in the abstract. I hope this high level review and kind request to the authors help -éric