Added remaining Alexey Melnikov's Gen-ART review comments:
In 2.2:

RTP and SIP need Informative references.

In 2.4:

PPP needs an Informative reference.

Also, where is IPv6CP defined?

Appendix B.  Changes to RFC 3316

I think that before publication this section needs to be reworked a bit to have a single list of changes, referencing particular draft versions is not going to be very useful in the final RFC.

Also changed the reference:
  draft-ietf-6man-nd-extension-headers to RFC6980.

Signed-off-by: Jouni Korhonen <jouni.korhonen@renesasmobile.com>