I have reviewed draft-ietf-softwire-public-4over6-09 as part of the security directorate's ongoing effort to review all IETF documents being processed by the IESG. These comments were written primarily for the benefit of the security area directors. Document editors and WG chairs should treat these comments just like any other last call comments. Draft is an opinion piece by a private member of the community who happens to wear several other hats. No protocol content. Other than a pro forma note that the draft contains no security considerations section, I have no security considerations per se with this document. The one observation I will make is that, having now been a participant in two serious cross-area efforts (probably more than that, but the two I'm thinking of are DNSSEC and SIDR), I have noticed that there does not appear to be any way of hurrying up the process of growing experts in a complex new topic. That is: when we started DNSSEC, we had security people and we had DNS people, the two groups were almost completely talking past each other, and the ops people were only sort of in the room. It took years to get to the point where we had people who really understood both topics, and longer to get ops to care. Jury is still out on SIDR, but it sure feels like the same curve. If there's any way to speed the process, I don't know what it is; attempts to force the pace seem more likely to result in messes that require yet another return to the drawing board.