Hello, I have reviewed this document 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. IMHO, the document is  ready . I just have one comment: The authors say that « as an informational overview, this draft does not introduce any extra security risks » and explain that future documents that specify practical solutions will detail the security aspects. They also refer to [RFC6325] for general TRILL security considerations. I may agree. However an informal document discussing problems and goals that practical solutions will have to address is also a good place to discuss general security aspects. Future documents could easily refer to this document while going further into details. Too bad. Cheers,    Vincent