RFC 6620, "FCFS SAVI: First-Come, First-Served Source Address Validation Improvement for Locally Assigned IPv6 Addresses", May 2012Source of RFC: savi (int)
Errata ID: 3927
Reported By: Leaf Yeh
Date Reported: 2014-03-21
Rejected by: Ted Lemon
Date Rejected: 2014-03-21
Section 2.5 says:
In order to provide proper source address validation, it is critical that the information distributed among the different FCFS SAVI devices be coherent.
It should say:
In order to provide proper source address validation, it is critical that the information distributed among the different FCFS SAVI devices be not coherent.
The above revision then complies with the other statements in the same paragraph:
In particular, it is important to avoid having the same source address bound to different binding anchors in different FCFS SAVI devices. Should that occur, then it would mean that two hosts are allowed to send packets with the same source address, which is what FCFS SAVI is trying to prevent. In order to preserve the coherency of the FCFS SAVI bindings distributed among the FCFS SAVI devices within a realm, the Neighbor Discovery (ND) protocol [RFC4861] is used, in particular the Neighbor Solicitation (NS) and Neighbor Advertisement (NA) messages.
The proposed change is incorrect. I think you have misunderstood what the word "coherent" means, and this led to confusion.