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. This document describes use of pseudo-nicknames for RBridges in an Active-Active Edge RBridge group. I am not familiar with TRILL but found the document to be well written and easy to follow. I did have one question, which may just be due to my lack of familiarity with relevant normative specs. The second paragraph of section 8 states the following: "However, for multi-destination TRILL Data packets, since they can reach all member RBridges of the new RBv and be egressed to CE1 by either RB2 or RB3 (i.e., the new DF for the traffic's Inner.VLAN or the VLAN the packet's Inner.Label maps to in the new RBv), special actions to protect against downlink failure for such multi-destination packets is not needed." Why is there no race condition between the arrival of multi—destination traffic and the creation of a new RBv following the failure of RB1 that enables the traffic to be forwarded? Generally, mentioning failure of the DF for the virtual RBridge seemed like it might warrant mention in the security considerations section, since that is new relative to the specs noted in the current security considerations.