It appears that the cost-based formulation for determining the extended P-space in draft-ietf-rtgwg-remote-lfa-02 is incorrect. In particular, section 4.2.2 says:
"In cost terms a router is in extended P-space if the shortest path cost S-N->P is strictly less than the shortest path cost S-E->P." Instead, the requirement should be that the shortest path cost N->P is strictly less than cost N-S-E->P. I propose the following text for section 4.2.2. "In terms of cost, a router Y is in the extended P-space of S with respect to the failure of link S-E, if either of the two following conditions is true: (1) D_opt(S,Y) < D_opt(S,E) + D_opt(E,Y) OR (2) S has a neighbor N satisfying the inequality: D_opt(N,Y) < D_opt(N,S) + D_opt(S,E) + D_opt(E,Y)" This text corrects the error noted above, and it puts both of the criteria for determining extended P-space in terms of cost in one place in the text. Chris
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