Robert,

As I understand it, the sub-TLV only became mandatory in the -12 version of the 
draft.  Comment inline.

Yours Irrespectively,

John



Juniper Business Use Only
From: Idr <[email protected]> On Behalf Of Robert Raszuk
Sent: Wednesday, June 26, 2019 2:32 PM
To: John E Drake <[email protected]>
Cc: [email protected]; Linda Dunbar <[email protected]>; [email protected]
Subject: Re: [Idr] Tunnel-Encap Gaps for SD-WAN described in 
draft-ietf-rtgwg-net2cloud-gap-analysis-02.txt

John,

> Making the Remote Endpoint sub-TLV mandatory effectively associates the 
> attribute with the remote endpoint.

I am not sure why you draw such conclusion.

Including remote endpoint address does not bind this sub-TLV to be advertised 
with the remote end point NLRI. Quite contrary this information is needed on a 
per NLRI basis.

How could you not send endpoint address if the entire purpose of this extension 
is to signal the address where the encapsulation should be terminated at - no ?

[JD] You could issue an UPDATE for the tunnel endpoint itself which contained 
the tunnel encapsulation attribute sans an endpoint sub-TLV.  Any routes that 
use that tunnel endpoint would also include the tunnel encapsulation attribute 
that contains only the endpoint sub-TLV.

Thx,
R.





On Wed, Jun 26, 2019 at 8:27 PM John E Drake 
<[email protected]<mailto:[email protected]>> 
wrote:
John,

Oopsie, I missed that.  Do we really want to have this behavior?  Having it 
optional would give us a lot more flexibility and I thought an attribute was 
supposed to be associated with a route.  Making the Remote Endpoint sub-TLV 
mandatory effectively associates the attribute with the remote endpoint..

Yours Irrespectively,

John



Juniper Business Use Only
From: John Scudder <[email protected]<mailto:[email protected]>>
Sent: Wednesday, June 26, 2019 2:06 PM
To: Linda Dunbar 
<[email protected]<mailto:[email protected]>>; John E Drake 
<[email protected]<mailto:[email protected]>>
Cc: [email protected]<mailto:[email protected]>; [email protected]<mailto:[email protected]>
Subject: Re: [Idr] Tunnel-Encap Gaps for SD-WAN described in 
draft-ietf-rtgwg-net2cloud-gap-analysis-02.txt

Linda, John,

Your discussion is premised on the assumption that the remote endpoint sub-TLV 
is optional. Consider this paragraph, from section 5:


   When the Tunnel Encapsulation attribute is carried in an UPDATE of

   one of the AFI/SAFIs specified in the previous paragraph, each TLV

   MUST have a Remote Endpoint sub-TLV.  If a TLV that does not have a

   Remote Endpoint sub-TLV, that TLV should be treated as if it had a

   malformed Remote Endpoint sub-TLV (see Section 
3..1<https://urldefense.proofpoint.com/v2/url?u=https-3A__tools.ietf.org_html_draft-2Dietf-2Didr-2Dtunnel-2Dencaps-2D12-23section-2D3.1&d=DwMFaQ&c=HAkYuh63rsuhr6Scbfh0UjBXeMK-ndb3voDTXcWzoCI&r=CRB2tJiQePk0cT-h5LGhEWH-s_xXXup3HzvBSMRj5VE&m=_zqphBlaANTkEVfQVx5NpmQ7-8RubppSD0iarWwp51Q&s=1dbuCL3WFhEoWoXW5XxAEW2M1XfSEbTAqXS0ywCbiQQ&e=>).

There's both a MUST clause and directions to ignore the sub-TLV if the remote 
endpoint is missing. To me this seems clear without any changes to the draft.

Regards,

-John

On Jun 21, 2019, at 8:25 AM, Linda Dunbar 
<[email protected]<mailto:[email protected]>> wrote:

John,

I am with you hoping that the Tunnel-encap authors can clarify more.
Based on the description of how the receivers of the Tunnel UPDATE msg add the 
Encapsulation Headers to client routes described in the Tunnel-Encap draft, it 
should be:

  *   If the "Remote endpoint" sub-TLV was present and containing the same 
address as the route itself, then the receivers of the Tunnel UPDATE would 
construct the encapsulation header with the Outer Destination Address equal to 
the "route itself" (which is carried in the Remote Endpoint sub-TLV).
I think this can be a serious problem.


  *   if the "Remote Endpoint" sub-TLV was not present, the receivers of the 
Tunnel UPDATE would assume the UPDATE originator's address as the Tunnel Remote 
end point.

If the processing behavior described above is NOT what the Tunnel-Encap draft 
intended, then the Tunnel-Encap draft needs to add text to clarify the 
description.

Nevertheless, do you have objections of those gaps that Tunnel-Encap and 
Secure-EVPN:

- Doesn't have the functionality that would help the C-PE to register its WAN 
Port properties. Some WAN ports are facing public internet with ISP assigned 
addresses that are in different address space than the SD-WAN address space, 
some WAN ports are assigned with private addresses which need to propagate NAT 
information to the trusted peers via Controllers, such as the virtual C-PEs 
instantiated in public Cloud DCs, and some WAN ports are facing the trusted 
MPLS network.

- For the same Client route, e.g. 10.1.x.x, attached to a C-PE, need to be 
encrypted when forwarding to the WAN ports facing untrusted network, and can be 
forwarded without any encryption towards WAN ports facing trusted network.


Thank you very much for the discussion. I have updated the Gap analysis to 
reflect what has been discussed in this email thread....

Linda

From: John E Drake <[email protected]<mailto:[email protected]>>
Sent: Friday, June 21, 2019 8:14 AM
To: Linda Dunbar 
<[email protected]<mailto:[email protected]>>; 
[email protected]<mailto:[email protected]>; [email protected]<mailto:[email protected]>
Subject: RE: Tunnel-Encap Gaps for SD-WAN described in 
draft-ietf-rtgwg-net2cloud-gap-analysis-02.txt

Linda,

It would be useful to get a clarification from the authors.  I had always 
thought that if the remote endpoint sub-TLV was either not present or present 
and containing the same address as the route itself, then the information in 
the tunnel encapsulation attribute pertains to the address specified in the 
route.  This is the assumption made in the Secure EVPN draft that I mentioned 
earlier in this thread.

Alternatively, the route could specify a loopback address of the C-PE and the 
tunnel encapsulation attribute could contain the interface address and 
characteristics of each of its WAN-facing ports; this is completely compliant 
with your interpretation that the address specified in the route is reachable 
through an address specified in the remote endpoint sub-TLV.

[Linda] But there is no field to indicate the property of the WAN ports.

Yours Irrespectively,

John


Juniper Internal
From: Linda Dunbar 
<[email protected]<mailto:[email protected]>>
Sent: Thursday, June 20, 2019 7:08 PM
To: John E Drake <[email protected]<mailto:[email protected]>>; 
[email protected]<mailto:[email protected]>; [email protected]<mailto:[email protected]>
Subject: RE: Tunnel-Encap Gaps for SD-WAN described in 
draft-ietf-rtgwg-net2cloud-gap-analysis-02.txt

John,

Those addresses stated in the quoted paragraphs are for Clients Routes, i.e.. 
the routes attached to the PE, not the PE's lookback address, correct?
The Loopback Address is specified in the "Remote Endpoint" SubTLV, so that 
receivers of the UPDATE can establish the Encapsulation with the outer 
destination address equal to the one specified by the "Remote endpoint" SubTLV.

That was discussed in the long email discussion thread last week.

We can ask the Tunnel-Encap authors to confirm.

Linda

From: John E Drake <[email protected]<mailto:[email protected]>>
Sent: Thursday, June 20, 2019 5:50 PM
To: Linda Dunbar 
<[email protected]<mailto:[email protected]>>; 
[email protected]<mailto:[email protected]>; [email protected]<mailto:[email protected]>
Subject: RE: Tunnel-Encap Gaps for SD-WAN described in 
draft-ietf-rtgwg-net2cloud-gap-analysis-02.txt

Linda,

>From section 5 on the Tunnel Encapsulation Attribute draft:

"[RFC5512] specifies the use of the Tunnel Encapsulation attribute in
BGP UPDATE messages of AFI/SAFI 1/7 and 2/7.  That document restricts
the use of this attribute to UPDATE messsages of those SAFIs.  This
document removes that restriction.

The BGP Tunnel Encapsulation attribute MAY be carried in any BGP
UPDATE message whose AFI/SAFI is 1/1 (IPv4 Unicast), 2/1 (IPv6
Unicast), 1/4 (IPv4 Labeled Unicast), 2/4 (IPv6 Labeled Unicast),
1/128 (VPN-IPv4 Labeled Unicast), 2/128 (VPN-IPv6 Labeled Unicast),
or 25/70 (Ethernet VPN, usually known as EVPN)).  Use of the Tunnel
Encapsulation attribute in BGP UPDATE messages of other AFI/SAFIs is
outside the scope of this document."

What this means is that the tunnel encapsulation draft can be use exactly
as I described in my previous email to describe the characteristics of
of an SD-WAN port.

Yours Irrespectively,

John


Juniper Internal
From: Linda Dunbar 
<[email protected]<mailto:[email protected]>>
Sent: Thursday, June 20, 2019 6:08 PM
To: John E Drake <[email protected]<mailto:[email protected]>>; 
[email protected]<mailto:[email protected]>; [email protected]<mailto:[email protected]>
Subject: RE: Tunnel-Encap Gaps for SD-WAN described in 
draft-ietf-rtgwg-net2cloud-gap-analysis-02.txt

John,

Thank you very much for the feedback.
Comments are inserted below:

From: John E Drake <[email protected]<mailto:[email protected]>>
<Snip>

-------------------------------------------

-       [Tunnel-Encap] doesn't have the functionality that would help the C-PE 
to register its WAN Port properties.

-       A SD-WAN tunnel, e.g. IPsec-based, requires a negotiation between the 
tunnel's end points for supported encryption algorithms and tunnel types before 
it can be properly established, whereas [Tunnel-Encap]  only allow the 
announcement of one endpoint's supported encapsulation capabilities for 
specific attached routes and no negotiation between tunnel end points is needed.

[JD]  What you need to do is implement the model described in  the Secure EVPN 
draft 
(https://tools.ietf.org/html/draft-sajassi-bess-secure-evpn-01<https://nam03.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense.proofpoint....com%2Fv2%2Furl%3Fu%3Dhttps-3A__nam03.safelinks.protection.outlook.com_-3Furl-3Dhttps-253A-252F-252Ftools.ietf.org-252Fhtml-252Fdraft-2Dsajassi-2Dbess-2Dsecure-2Devpn-2D01-26data-3D02-257C01-257Clinda.dunbar-2540futurewei.com-257C28557a27c1c64de4997708d6f5b30f7f-257C0fee8ff2a3b240189c753a1d5591fedc-257C1-257C1-257C636966546754208641-26sdata-3DqLd2LVx5Lng7QccAIB0weIfpXE3IBOQfq0kiLUJqFMs-253D-26reserved-3D0%26d%3DDwMFAg%26c%3DHAkYuh63rsuhr6Scbfh0UjBXeMK-ndb3voDTXcWzoCI%26r%3DCRB2tJiQePk0cT-h5LGhEWH-s_xXXup3HzvBSMRj5VE%26m%3Dv-ZrS-NTEa3rPqhwNaoM5gNU8iL1zGd7DutDZaH0C4w%26s%3DnivOMac2lUDvbaJX-GTBeiLAWMqfyKOsTpqvG3AB27A%26e%3D&data=02%7C01%7Clinda.dunbar%40futurewei..com%7C84c6ed1f7cb342efda1208d6f64a6827%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C636967196777678003&sdata=3wnRuxLXyDo9qPVXcIfbGNWZMNC37wef0hd4kBJlEWQ%3D&reserved=0>).
  Viz, the SD-WAN C-PEs are attached to a route reflector and each uses the 
route reflector to advertise its security-related  information the other C-PEs. 
 As we discussed in Prague the tunnel encapsulation attribute is not associated 
with client routes.  Rather it is associated with the loopback or interface 
addresses of the advertising SD-WAN C-PE.  I.e., IPv4/IPv6 addresses rather 
than VPN IPv4/IPv6 addresses

[Linda]Yes, using Loopback address would be a good way for tunnel, but that is 
not what Tunnel-Encap specified. The draft Tunnel-Encap is to advertise 
supported Encap capabilities for specified routes.
I have another section (4.3) on the gap analysis for SECURE-EVPN, specifically, 
Secure-EVPN does not address the scenario of C-PE having some ports facing 
trusted MPLS VPN and other ports facing the untrusted public Internet. The 
document assumes that a client route is either forwarded all encrypted through 
one tunnel, or not encrypted at all through a different tunnel. In SD-WAN, one 
client route can be forwarded encrypted at one time through the untrusted 
network and be forwarded unencrypted at different time through MPLS VPN.
If you think the secure-evpn has addressed those scenarios, can you please 
indicate which section? Thank you.


The establishment of a SD-WAN tunnel can fail, e.g., in case the two endpoints 
support different encryption algorithms. That is why a SD-WAN tunnel needs to 
be established and maintained independently from advertising client routes 
attached to the edge node.

[JD]  See above

-       [Tunnel-Encap] requires all tunnels updates are associated with routes. 
There can be many client routes associated with the SD-WAN IPsec tunnel between 
two C-PEs' WAN ports; the corresponding destination prefixes (as announced by 
the aforementioned routes) may also be reached through the VPN underlay without 
any encryption.. A more realistic approach to separate SD-WAN tunnel management 
from client routes association with the SD-WAN tunnels.

[JD]  See above

-       When SD-WAN tunnel and clients routes are separate, the SD-WAN Tunnel 
establishment may not have routes associated.
There is a suggestion on using a "Fake Route" for a SD-WAN node to use 
[Tunnel-Encap] to advertise its SD-WAN tunnel end-points properties. However, 
using "Fake Route" can raise some design complexity for large SD-WAN networks 
with many tunnels. For example, for a SD-WAN network with hundreds of nodes, 
with each node having many ports & many endpoints to establish SD-WAN tunnels 
with their corresponding peers, the node would need as many "fake addresses". 
For large SD-WAN networks (such as those comprised of more than 10000 nodes), 
each node might need 10's thousands of "fake addresses", which is very 
difficult to manage and requires lots of configuration tasks to get the nodes 
properly set up.

[JD]  There is no need for a 'Fake Route'.  We advertise a tunnel encapsulation 
attribute with security-related information for a specific SD-WAN port on the 
C-PE as identified by its IPv4/IPv6 interface address.  If a set of SD-WAN 
ports have common security-related information a tunnel encapsulation attribute 
can be advertised with a C-PE's loopback address.

[Linda] this section is for Tunnel-Encap, which doesn't allow Loopback address 
to be associated with the tunnel. If you think it does, can you please indicate 
which section? Thank you.

Linda

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