Jim Bound: I also believe that the problem that is being solved is most critical for wireless media networks and NOT for most wireline networks or those secured by physical access prohibition, and are simply physically secure. Most nodes in production use are in fact today wireline, or physically secure and not public wireless. I personally believe that will change in the next 5 years and it is good the IETF community is addressing this important issue, but it is not the case today. To this end I would suggest the specification make it clear where this technology change is required and useful and make it clear they are addressing non physically secure networks. That would provide a clear honest statement of need, and call to action for implementation for the correct target. Networks running in a secured physical enviornment simply do not need this functionality, and the performance costs of this enhancement with this enhancement into NDP at all. ----- I think this is a good suggestion, we appear to need a better description of this in the Security Considerations section. But I think the issue itself is somewhat more complex than wireless/wireline. For instance, other (L2) security mechanisms provide partial help in some cases. Registered as issue #74. And Jim, some of us have gone wireless-only already years ago... ----- Jari Arkko: Here is the change that I added to Section 1: The SEND protocol is designed to counter the threats to NDP. These threats are described in detail in . SEND is applicable in environments where physical security on the link is not assured (such as over wireless) and attacks on NDP are a concern.