RE: DMTF SAAction restriction

[Man.M.Li@xxxxxxxxx]

Is the "try until one succeeds" being described in any RFCs or is it only
ONE way of implementation? I recall ISAKMP allow initiator to propose
multiple proposals and multiple transforms for responder to choose from. But
I do not recall seeing this "try until one succeeds". 


Man Li
Nokia 
5 Wayside Road, Burlington, MA 01803
man.m.li@xxxxxxxxx
phone 1-781-993-3923
GSM 1-781-492-2850 

-----Original Message-----
From: ext Lee Rafalow [mailto:rafalow@xxxxxxxxxxxxxxx]
Sent: Tuesday, February 06, 2001 9:48 AM
To: ipsec-policy@xxxxxxx
Subject: Re: DMTF SAAction restriction


The approach that we've thought through so far would use your first example
to set up the tunnel.  We could explore your suggestion to add a sematic to
the action list, but that complicates it significantly.  We already have
semantics for the initiator and responder that are variations on "try until
one succeeds."  Recall that for the initiator it's try the first one, if
that fails try the second, etc.  For the responder it's a little more
complicated: respond from the first action that is appropriate to the
request (this allows a single rule to deal with both aggressive and main
mode requests).


To add semantics for "do ordered list of actions" would require a fairly
complicated grammar for grouping actions into execution strategy groups (do
all, do first successful).

A way out of this might be to use the structured rules being proposed in the
PCIM Extensions draft (currently being written) but that'll have to wait
until we have a PCIMe draft to discuss.

Lee
----- Original Message -----
From: <Man.M.Li@xxxxxxxxx>
To: <HORMAN@xxxxxxxxxx>; <ipsec-policy@xxxxxxx>; <jamie.jason@xxxxxxxxx>;
<Man.M.Li@xxxxxxxxx>
Sent: Monday, February 05, 2001 4:14 PM
Subject: RE: DMTF SAAction restriction


> Security per se may not be a problem. But if only a small percentage of
> traffic needs multiple nested protection and we end up with giving all the
> traffic multiple protections, it would be a waste of resources (e.g.,
> processing resource for encryption). Security comes with a price and I
> question if service providers or corporate IT managers will be happy about
> giving the free ride at the expense of network resources.
>
> Man Li
> Nokia
> 5 Wayside Road, Burlington, MA 01803
> man.m.li@xxxxxxxxx
> phone 1-781-993-3923
> GSM 1-781-492-2850
>
> -----Original Message-----
> From: ext Hilarie Orman [mailto:HORMAN@xxxxxxxxxx]
> Sent: Monday, February 05, 2001 3:10 PM
> To: ipsec-policy@xxxxxxx; jamie.jason@xxxxxxxxx; Man.M.Li@xxxxxxxxx
> Subject: RE: DMTF SAAction restriction
>
>
> Why would it be erroneous to include a tunnel gratuitously?
> Wrt to security, what is the problem?
>
> Hilarie
>
> >>> <Man.M.Li@xxxxxxxxx> 02/05/01 11:22AM >>>
> What selectors are you looking for in your second search after the
transport
> rule? Is it a selector for the already encrypted packets (hence protocol =
> ESP, for example) or for the original packets (protocol = tcp)? I see
> problems in both cases. In the first case, if there is a rule to set up a
> tunnel for ESP packets, we may include some other traffic that are ESP
> transport protected but should not be included in the tunnel. In other
> words, those traffic should only be transport protected.
>
> In the second case, we cannot reach the second selector for tunnel set up
> because first matches will stop the search.
>
> A simple solution would be to remove the restriction and let SAActions to
> indicate an ordered list of actions to be executed.
>
> Man Li
> Nokia
> 5 Wayside Road, Burlington, MA 01803
> man.m.li@xxxxxxxxx
> phone 1-781-993-3923
> GSM 1-781-492-2850
>
> -----Original Message-----
> From: ext Jason, Jamie [mailto:jamie.jason@xxxxxxxxx]
> Sent: Monday, February 05, 2001 11:01 AM
> To: 'Man.M.Li@xxxxxxxxx'; ipsec-policy@xxxxxxx
> Subject: RE: DMTF SAAction restriction
>
>
> Lee can correct me if I am wrong on this one, but I believe we had this
same
> discussion during a conference call between Lee, Eric Vyncke, and myself.
I
> believe the solution we came up with was that policy evaluation would
first
> encounter the transport rule.  Policy evaluation would then search to
> determine if there was a tunnel rule that would apply (it would do this
> recursively as you may have tunnels in tunnels).  This update probably
> hasn't hit the MOF file or whitepaper yet.
>
> Jamie
>
> > -----Original Message-----
> > From: Man.M.Li@xxxxxxxxx [mailto:Man.M.Li@xxxxxxxxx]
> > Sent: Monday, February 05, 2001 7:16 AM
> > To: ipsec-policy@xxxxxxx
> > Subject: DMTF SAAction restriction
> >
> >
> > Hi,
> >
> > The DMTF policy model Section 3 first paragraph indicates
> > "The IPsec model
> > restricts the use of SAActions to an ordered choice rather
> > than a list of
> > actions to be executed." I am wondering how the following
> > situation would be
> > handled with this restriction. We had similar discussions
> > among IPsec PIB
> > authors.
> >
> >        A (host)===========C(gateway)---B(host)
> >
> > A and C are connected to public Internet and B is connected
> > to C. To protect
> > TCP traffic between hosts A and B, an IPsec security association in
> > transport mode needs to be established between hosts A and B.
> > In addition,
> > an IPsec security association in tunnel mode may be set up
> > between host A
> > and the gateway C that protects the LAN host B resides.
> >
> > In this case, A takes one action to set up an association
> > between A and B.
> > In addition, A should also set up a tunnel between A and C.
> > From A's point
> > of view, there are MULTIPLE actions to be taken in that order.
> >
> > How would you specify a policy to A if you are not allowed to
> > specify a list
> > of actions to be executed?
> >
> >
> > Man Li
> > Nokia
> > 5 Wayside Road, Burlington, MA 01803
> > man.m.li@xxxxxxxxx
> > phone 1-781-993-3923
> > GSM 1-781-492-2850
> >