Re: [dhcwg] Stephen Farrell's Discuss on draft-ietf-dhc-dhcpv6-active-leasequery-03: (with DISCUSS and COMMENT)

[Kim Kinnear <[e-mail]>]

On Jul 8, 2015, at 7:42 AM, Stephen Farrell <[e-mail]> wrote:

> - section 10: why is (the usually mythical:-) 3315 a MUST NOT
> here? I don't get that. I could see it being an EDONTCAR but I
> don't see the harm if one did go mad and try use 3315. And I
> could maybe, possibly, with a lot of a nose-holding, see a
> universe in which one might use TLS server auth for the DHCP
> server and 3315 to authenticate the requestor, so it seems odd
> to rule that out in this way.

Stephen,

This language was in the first draft submission of this protocol,
so it wasn't something added along the way.  I would say that
the arguments for this language are:

  1. If you want authentication, use TLS which is a documented part of
  this protocol.

  2. The RFC 3315 authentication explicitly does not deal with data
  security, and so again, TLS gives you that.

  3. RFC 3315 authentication has not been specified over a TCP
  connection to the DHCP server.  Are there things you would need to
  think about here?  I can't think of any right off, but it still
  makes a nice argument.

  4. Why allow *two* security/authentication mechanisms for one
  protocol.  Yes, we could imagine someone using it, but if some
  people use it and some people use TLS, then where does that leave
  us?  Not communicating securely, seems to me. 

Bottom line:  Just because we can imagine someone doing this doesn't
make it a good thing to do.  So, I would say:  If you want
authentication or security, use TLS.  If not, not.  I see zero value
in allowing an intermediate solution which just makes the likelihood
of actually communicating significantly less.

I think this statement -- MUST NOT use 3315 authentication -- should
stand.

Regards -- Kim