Subject: Re: How to use properly ipv6 autoconf over a router interface?
To: Brian Ginsbach <>
From: Steven M. Bellovin <>
List: tech-net
Date: 05/05/2006 00:10:46
On Fri, 5 May 2006 03:46:43 +0000, Brian Ginsbach <>

> On Thu, May 04, 2006 at 11:52:11PM +0200, Hubert Feyrer wrote:
> > On Thu, 4 May 2006, Steven M. Bellovin wrote:
> > >>Seems like RSIP (RFC 3102-3105) could work well here.
> > >>
> > >RSIP is a form of NAT.  It's cleaner and better than traditional NAT, but
> > >it is NAT-like.  Also note that the protocols are experimental, not
> > >standards track.  I don't think anyone has tried to use them with v6.
> > 
> > Indeed, the IESG note at the top of RFC 3102 looks scary enough not to go 
> > too near:
> > 
> >    The IESG notes that the set of documents describing the RSIP
> >    technology imply significant host and gateway changes for a complete
> >    implementation.  In addition, the floating of port numbers can cause
> >    problems for some applications, preventing an RSIP-enabled host from
> >    interoperating transparently with existing applications in some cases
> >    (e.g., IPsec).  Finally, there may be significant operational
> >    complexities associated with using RSIP.  Some of these and other
> >    complications are outlined in section 6 of RFC 3102, as well as in
> >    the Appendices of RFC 3104.  Accordingly, the costs and benefits of
> >    using RSIP should be carefully weighed against other means of
> >    relieving address shortage.
> > 
> I read this with a large grain of salt as I understand from one of
> the authors there were a lot of IEFT politics involved...  And this
> sounds like a purely political statement.
I don't think it was IETF politics, and I was on the IAB at the time.  (If
I recall correctly, I was even the IAB liason to the IESG then.)
Basically, there just wasn't enough energy behind it. Some people, myself
included, really liked it, but not enough people did. As the IESG noted,
there were unresolved technical issues. These may have been solvable, but
there weren't enough people who wanted to solve them.

Remember that 

		--Steven M. Bellovin,