Subject: comments about draft-ietf-6man-dad-proxy-02

From: Tassos Chatzithomaoglou <[email-masked]>
Date: Tue, 27 Mar 2012 13:46:55 +0200

Some questions/comments about this draft:

1) I think it should be better to provide an alternative terminology in 
order to better describe the topology, like hub and spokes or root and 
leaf(s).
2) IPv6 over PPP is not affected and should probably be mentioned.

3)  Under 4.2.2, i believe there is a mixup of CPE states.
i.e. according to the following, CPE1 has already a cache entry

The BNG then has to
    verify whether there is a real conflict by checking if the CPE whose
    IPv6 address is in the entry is still connected.  In the following,
    we will call IPv6-CPE1 the IPv6 address of the existing entry, Link-
    layer-CPE1 the Link-layer address of that entry and Link-layer-CPE2
    the Link-layer address of the CPE which is performing DAD, which is
    different from Link-layer-CPE1.

but then, the following paragraphs talk about different CPE1 cache states.

If IPv6-CPE1 is in the Neighbor Cache, but it is associated with
       another Link-layer address than Link-layer-CPE1...

If IPv6-CPE1 is not in the Neighbor Cache...

The last one surely contradicts the "we will call IPv6-CPE1 the IPv6 
address of the existing entry" statement.
It also seems a little bit confusing to me.

4)

If IPv6-CPE1 is in the Neighbor Cache, but it is associated with
       another Link-layer address than Link-layer-CPE1, that means that
       there is possibly a conflict with another CPE, but that CPE did
       not perform DAD.  This situation is out of the scope of this
       document, since one assumption made above is that all the nodes of
       a point-to-multipoint domain (except the DAD proxy itself) perform
       DAD.  This case could be covered in the future by additional
       solutions that work in conjunction with the DAD proxy.

Would it be an intermediate solution to delete all "possibly wrong" 
entries and/or log an error message?

-- 
Tassos