Hi Linda 

After reading this document I realized this is an informational draft although 
very technical with details packet walk.

Is there a new IANA AFI/SAFI assigned to this new bgp capability for 
provisioning SD WAN endpoints.

Also is there an RFC that describes this BGP SDWAN new capability.

I need to read that document before reading this draft to help connect the dots 
on how this is going to work.

Thank you 

Gyan

Sent from my iPhone

> On Nov 19, 2019, at 3:22 AM, Linda Dunbar <[email protected]> wrote:
> 
> Gyan,
>  
> Traditional IPsec is point to point. Each node has to be configured with 
> remote subnets on the remote node as well as the certificate.
> For SDWAN Zero Touch Provisioning, each node doesn’t know who is authorized 
> to communicate with him.
>  
> By leveraging BGP UPDATE sending to its RR, RR can use the policy and 
> certificate management stored in RR to propagate to a set of CPEs that are 
> authorized to communicate with the node. Each node doesn’t need to worry 
> about the remote nodes’ certificate, doesn’t need to validate who can 
> communicate with him. Each node only to send out its public key and 
> authentication methods (AH or ESP).
>  
> As the result, the number of messages to maintain IPsec key among a group of 
> nodes is much less.
>  
> For example,
>  
> <image003.png>
>  
> Linda
>  
> From: Gyan Mishra <[email protected]> 
> Sent: Saturday, November 16, 2019 3:13 PM
> To: Linda Dunbar <[email protected]>
> Cc: Robert Raszuk <[email protected]>; [email protected]
> Subject: Re: [bess] Any protocols suitable for Application Flow Based 
> Segmentation in draft-bess-bgp-sdwan-usage-3?
>  
> Linda 
>  
> So with this new SDWAN architecture it would eliminate the need for DMVPN 
> NHRP based proprietary VTI tunnel mode architecture or any IPSEC hub/spoke 
> architecture and all would be done via an SDWAN controller that does the 
> discovery and builds the bgp session from all the SDWAN endpoints to the RR 
> controller and all the tunnels are ZTP provisioned and comes up.
>  
> Does this solution use BGP AD? similar to what is used for MVPN EVPN VPLS etc.
>  
> Since you still have to maintain all the IPSEC IKEv2 SAs what makes this 
> solution with BGP scale better then traditional IPSEC hub/spoke overlay with 
> SDWAN MP-MP overlay.
>  
> Gyan
>  
> Sent from my iPhone
> 
> On Nov 14, 2019, at 6:47 AM, Linda Dunbar <[email protected]> wrote:
> 
> Gyan,
>  
> Thank you very much for providing the examples. Yes, DMVPN or DSVPN has been 
> used for SD-WAN. We used them too for network less than 100 nodes.
> For routers that already have BGP protocol stack, it is easier to leverage 
> the BGP UPDATE to propagate the information.
>  
> draft-bess-bgp-sdwan-usage is an informational draft showing how BGP is used 
> for some SDWAN Scenarios. The purpose of the draft is to show to the industry 
> IETF’s protocols work well. (p.s. DMVPN or DSVPN is not IETF standard, they 
> both use vendors extended version of NHRP). Hope to discuss with you more.
>  
> For example,
>  
> <image001.png>
> <image002.png>
>  
> Looking for more comments,
>  
> Linda
>  
>  
> From: Gyan Mishra <[email protected]> 
> Sent: Wednesday, November 13, 2019 7:39 AM
> To: Linda Dunbar <[email protected]>
> Cc: Robert Raszuk <[email protected]>; [email protected]
> Subject: Re: [bess] Any protocols suitable for Application Flow Based 
> Segmentation in draft-bess-bgp-sdwan-usage-3?
>  
>  
> Sorry to talk implementation on or off list but from a pure net-net vpn VTI 
> tunnel mode perspective using DMVPN that scales pretty well to 100’s of user 
> sites homing to a pair of mGRE DMVPN head ends which I have deployed.  I have 
> not done any with over a 1000 on a pair but that’s a lot even for any mpls 
> deployments I have worked with.  The IPSEC SA is all done with hardware 
> encryption and so the scaling is very high for most all vendors the maximum 
> number of IPSEC tunnels that can be hit.
>  
> I would say a similar analogy would be that most SP routers support 1M+ FIB 
> entires per customer VRF on average per vendor which is way high and its rare 
> that you have an L3 VPN that exceeds 1M routes.  These days the hardware far 
> exceeds the possible use cases.
>  
> Gyan
> 
> Sent from my iPhone
> 
> On Nov 5, 2019, at 6:50 PM, Linda Dunbar <[email protected]> wrote:
> 
> Robert,
>  
> Without getting into any implementation, are there any terrible problems of 
> allowing IPsec tunnel as transport segment and each edge node forward packets 
> destined to other nodes, as done by VRF. What issues do you see? (other than 
> it is not IPsec tunnel per client interface/group)?
>  
> <image002.png>
>  
> Thanks, Linda
>  
> From: Robert Raszuk <[email protected]> 
> Sent: Tuesday, November 05, 2019 5:21 PM
> To: Linda Dunbar <[email protected]>
> Cc: [email protected]
> Subject: Re: [bess] Any protocols suitable for Application Flow Based 
> Segmentation in draft-bess-bgp-sdwan-usage-3?
>  
> > it is tremendous amount of work.  
>  
> Well I am afraid this is entering implementation space and not subject to any 
> further debate on or off the list. Only note that IPSec is not the only 
> payload encryption option at your disposal for quality SDWANs.
>  
> On Tue, Nov 5, 2019 at 11:07 PM Linda Dunbar <[email protected]> wrote:
> Robert,
>  
> It is not the FIB size, but the number of IPsec SA maintenance required at 
> each edge node that makes it difficult to scale more than 100 nodes.
> Each IPsec SA requires periodical key refreshment. For one node maintaining X 
> number of IPsec SA, it is tremendous amount of work.
>  
> Linda
>  
> From: Robert Raszuk <[email protected]> 
> Sent: Tuesday, November 05, 2019 3:15 PM
> To: Linda Dunbar <[email protected]>
> Cc: [email protected]
> Subject: Re: [bess] Any protocols suitable for Application Flow Based 
> Segmentation in draft-bess-bgp-sdwan-usage-3?
>  
> Linda,
>  
> The key message here is that in properly designed SDWAN your limit is capped 
> by volume of data traffic required to be encrypted and supported by your 
> platform. Number of overlay adjacencies does not matter. 
>  
> It does not matter since the size of your FIB has orders of magnitude more 
> capacity then any single SDWAN number of endpoints. 
>  
> Best,
> R,
>  
> On Tue, Nov 5, 2019 at 9:20 PM Linda Dunbar <[email protected]> wrote:
> Robert,
>  
> You said “It has been deployed and is fully operating with no concern of 
> scalability for number of years at least from one vendor I am aware of.”
>  
> How many nodes of this deployment?
>  
> As you described: just two nodes might need 18 IPsec tunnels. How about 100 
> node SDWAN network? 100*99 * 18?
>  
> “So number of overlay pipes to be created in corresponding SDWAN data planes 
> is 9 in each direction just over those *two* end points. 18 if you consider 
> bidirectional traffic”
>  
> Linda
>  
> From: Robert Raszuk <[email protected]> 
> Sent: Monday, November 04, 2019 6:54 PM
> To: Linda Dunbar <[email protected]>
> Cc: [email protected]
> Subject: Re: [bess] Any protocols suitable for Application Flow Based 
> Segmentation in draft-bess-bgp-sdwan-usage-3?
>  
> Hi Linda,
>  
> > Overlay, the multipoint to multipoint WAN is an overlay network. If using 
> > IPsec 
> > Point to Point tunnel, there would be N*(N-1) tunnels, which is too many to 
> > many.  
>  
> Please observe that any to any encapsulated paths setup in good SDWAN is day 
> one requirement. And that is not only any src/dst to any src/dst. It is 
> actually from any source interface over any available underlay to any 
> available remote interface of the destination. 
>  
> Imagine if you have two end points each with three interfaces to the 
> underlay. So number of overlay pipes to be created in corresponding SDWAN 
> data planes is 9 in each direction just over those *two* end points. 18 if 
> you consider bidirectional traffic. 
>  
> Good SDWAN can build such state and not only that .. it can also run in 
> continued fashion SLA probes over all possible paths between given src and 
> destination. When data is sent over selected per application path it is then 
> encrypted. It can even do much more ... it can perform SDWAN-TE treating some 
> endpoints as transits :).  
>  
> It has been deployed and is fully operating with no concern of scalability 
> for number of years at least from one vendor I am aware of. So I question 
> your observation and do believe that adding vrf based routing over well 
> designed and correctly written SDWAN is of any scalability concern. As a 
> matter of fact the implementation I am familiar with also has built in 
> concept of VRFs too. 
>  
> No it is not trivial - but clearly possible. 
>  
> Best,
> Robert. 
>  
>  
> On Mon, Nov 4, 2019 at 11:39 PM Linda Dunbar <[email protected]> wrote:
> In MEF SD-WAN Service Specification WG, there has been a lot of discussion on 
> Application Flow Based Segmentation.
> Application Flow based Segmentation refers to separating traffic based on 
> business and security needs, e.g. having different topology for different 
> traffic types or users/apps.
> For example, retail business requires traffic from payment applications in 
> all branches only go to the Payment Gateway in its HQ Data Centers, whereas 
> other applications can be multi-point (in Cloud DC too).
> Segmentation is a feature that can be provided or enabled for a single SDWAN 
> service (or domain). Each Segment can have its own policy and topology.
> In the figure below, the traffic from the Payment application (Red Dotted 
> line) is along the Tree topology, whereas other traffic can be multipoint to 
> multi point topology as in VRF.
>  
> <image001.jpg>
>  
>  
> Segmentation is analogous to VLAN (in L2 network) and VRF (in L3 network). 
> But unlike VRF where all the intermediate nodes can forward per VRF, in SDWAN 
> Overlay, the multipoint to multipoint WAN is an overlay network. If using 
> IPsec Point to Point tunnel, there would be N*(N-1) tunnels, which is too 
> many to many.
>  
> Does anyone know an existing protocol that can handle the above scenario 
> described in 
> https://datatracker.ietf.org/doc/draft-dunbar-bess-bgp-sdwan-usage/
>  
>  
> Thank you very much.
>  
> Linda Dunbar
>  
>  
>  
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