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.

THe document describes the Multicast Listener Discovery protocol version 2 (MLDv2) for IPv6. This protocol allows IPv6 routers to discover the presence of multicast listeners on directly attached links, and to discover which multicast addresses are of interest to these listeners. The draft is well written and easy to understand. There are few issues though, that relate to security of the protocol.

I think that the Security Consideration section should be expanded and be rewritten in a more structural way. In particular, it should be mentioned that the protocol lacks any cryptographic protection, thus its messages are not authenticated, provide no confidentiality and can be replayed. Then I would discuss the consequences of each of these deficiencies. 

The lack of replay protection seems to have no effect on the protocol security, because it is (at least it should be) designed so that it tolerates IP packets duplication (correct me if I'm wrong, I read the protocol itself briefly, but this was my impression).

The lack of authentication leads to possible message forgery. The corresponding attacks are described in the draft, however, I'm not sure taht the list is complete. For example, it seems to me that forged Current State Report message from a malicious node may report a lot number of faked listening multicast addresses, aiming to consume router's resources (a kind of DoS attack).

The lack of confidentiality is not discussed in the draft. In fact, it leads to privacy issues - any passive attacker on the local link can learn what multicast addresses other nodes are listen to, which may be quite sensitive information.