Re: Secdir last call review of draft-ietf-lisp-rfc6830bis-15

[Luigi Iannone <ggx@xxxxxxxxx>]

Kyle, Dino,

I fill like this discussion is going sideways w.r.t. the original 6830bis document.

You started to discuss other documents and other solutions, which, while certainly interesting and important, belong to other threads and documents.

IMHO here are the few points that need to be clarified:

On 28 Aug 2018, at 23:48, Kyle Rose <krose@xxxxxxxxx> wrote:

Hi, Dino. I have additional responses inline.

> For the internet core (DFZ RIB) use-case, LISP proposes replacing BGP sessions
> and global eventually-consistent state sharing with a global control plane and

LISP *does not propse to eliminate BGP*, in fact it needs it so RLOC reachability across the network is available, or there would be no underlay for the LISP overlay.

The whole point of LISP is to create a routing overlay for the EID address space, the RIB of which is managed by a global mapping system, not BGP sessions. If control plane traffic managed by BGP (or static routes, or whatever networks use once the DFZ RIB is limited to entities in the core) continues to flow, that is of small comfort to end users trying to get data over the data plane. >From the perspective of end users, BGP is being replaced routing of the traffic that matters to them.

Maybe this is just splitting hairs: I certainly don't want to rathole on this point.

@Kyle: can we consider this point closed?

[trimmed]

https://tools.ietf.org/html/draft-ietf-lisp-sec-15#ref-I-D.ietf-lisp-rfc6833bis

> One area of concern, of which I have not been able to find discussion, is that
> of the implications of shared capacity for the control and data planes, and how
> this can allow a volumetric data plane attack to deny a router access to the
> global mapping system, slowly choking off service to uncached portions of the

Well yes, this happens with all our IETF protocols. It is a valid concern and there are many operational techniques in network infrastructure that *help* solve (but not eliminate) these problems.

I would like to see a discussion of whether and how the nature and scale of this problem differs from that of the status quo. BGP sessions and RIB push have properties that are well-established from decades of experience: surely LISP does not have exactly the same properties. The security considerations should make clear, for instance, how a loss of control plane connectivity differs from the loss of a BGP session, and how this impacts visibility and behavior of the data plane.

 

I am not sure I understand the point. Isn’t this covered by RFC7835? Reference to that document isn’t sufficient?

If not, can you clarify further?

> I would also like clarification on what defines the separation between the
> control plane and data plane, and whether authentication itself is used to

A control-plane obtains information to store in a table. The data-plane uses that table. That is the definition in the simpliest form.

I mean specific to LISP, not generically. For instance, does "LISP Control-Plane signaling" include only valid messages, or valid + inauthentic (and presumably dropped) messages? Traditional attack traffic (e.g., a DDoS attack against a website) is part of the same data plane as all legitimate end user traffic; is attack traffic directed at control plane endpoints considered part of the control plane, or is it a third category of traffic? If the latter, then what does an operator need to do to ensure that control plane is always available?

IMHO, these questions should be asked for in the 6833bis thread. Don’t you guys agree?

Ciao

L.

Kyle