Hi, IIRC, it was mentioned in HNL that the cost() function should have its own little subsection describing what it does in one place. I'm trying to do that right now (see the cost_fn branch).... While working on that, I also noticed that LoopFree() is described in the Metrics section. I know I'm pretty late to the party here, but this seems a bit counterintuitive to me. What's the reason this was put in the Metric section and not, for example, in the sections describing how to handle an incoming RteMsg? Cheers, Lotte