Re: [Idr] Seeking feedback of draft-dunbar-idr-sdwan-port-safi using SDWAN SAFI to encode SDWAN Instance ID in the NLRI

[Robert Raszuk <[e-mail]>]

Hi Linda,

Nope you do not need VRFs. RT construct works at the control plane level.
VRF may be useful for traffic separation purposes on multitenant CPEs or if
you would like to relax requirements for unique IP across SDWAN sites - but
not a must otherwise.

My main point was  that BGP SAFI 128 gives you for free transport for
multiple routing contexts so why not leverage it as is?

Moreover you may suddenly also discover that RTC (RFC4684) is your
SDWAN friend too.

Many thx,
R.




On Tue, Mar 24, 2020 at 5:15 AM Linda Dunbar <[e-mail]>
wrote:

> Robert,
>
>
>
> Thank you very much for the feedback.
>
>
>
> If using your suggested Route Target approach to represent the SDWAN
> Instance ID, does it mean that a SDWAN Edge has to use the same approach to
> configure the VRF for SDWAN instances?
>
> If the edge node supports both traditional VPN and SDWAN, will it cause
> confusion for RT to represent both?
>
>
>
> RT is encoded in the Extended_Communities Path Attribute, SAFI 128 is
> encoded in the MP_REACH_NLRI Path Attribute.
>
>
>
> What do you mean by saying “different name to Route target(s) carried in
> the SAFI 128”?
>
> Do you mean having a different name (say SDWAN_Target) in
> Extended_Communities Path Attribute, and have MP_REACH_NLRI Path Attribute
> including the SAFI 128?
>
>
>
> SDWAN Instance ID is for the control Plane, not to be carried by the data
> packets. SAFI 128 for VPN has the Label encoded in the NLRI field that is
> to be carried by the data packets. But SDWAN Instance ID is not carried by
> the Data Packets. Is it correct?
>
>
>
> Thank you.
>
> Linda
>
>
>
>
>
>
>
>
>
> *From:* Robert Raszuk <[e-mail]>
> *Sent:* Monday, March 23, 2020 2:28 PM
> *To:* Linda Dunbar <[e-mail]>
> *Cc:* Huaimo Chen <[e-mail]>; [e-mail]; [e-mail]
> *Subject:* Re: [Idr] Seeking feedback of draft-dunbar-idr-sdwan-port-safi
> using SDWAN SAFI to encode SDWAN Instance ID in the NLRI
>
>
>
> Hi Linda,
>
>
>
> I think you are mixing data plane and control plane.
>
>
>
> In SDWAN data plane is of no issue as you are interconnecting sites in a
> given VPN over mesh of secure tunnels.
>
>
>
> You are asking how to keep control plane separate between VPN instances.
> This is precisely what RFC4364 does already and RT import/export is used to
> indicate the instance which given set of reachability belongs. Why to
> reinvent the wheel and do something new just for the heck of it :) ?
>
>
>
> To be original you can at best invent a different name to Route target(s)
> carried in the SAFI 128 but let's keep the mechanism the same. That would
> be my suggestion.
>
>
>
> Kind regards,
>
> R.
>
>
>
> PS. While this is obvious for some many folks are still confused. RFC4364
> does not need to run over MPLS data plane. It can run over IPSec or over
> DTLS or over UDP/IP just fine.
>
>
>
> On Mon, Mar 23, 2020 at 6:47 PM Linda Dunbar <[e-mail]>
> wrote:
>
> IDR experts:
>
>
>
> SDWAN is an overlay network arching over multiple types of networks. A
> SDWAN edge node may need to map client traffic to different SDWAN network
> instances (or segmentations).
>
> It might not be feasible to use the AS number in the BGP message to
> differentiate the SDWAN network instances as multiple SDWAN instances may
> share the same AS number.
>
>
>
> We would like to hear feedback from IDR group on using similar method as
>  Binding MPLS Labels to Address Prefixes [RFC8277] to bind SDWAN Instance
> ID to  prefixes.
>
>
>
> When  MPLS VPN SAFI (=128) is present, MPLS label is carried by NLRI
> [RFC8277] as:
>
>
>
>       0                   1                   2                   3
>
>       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
>
>      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>
>      |    Length     |                 Label                 |Rsrv |S|
>
>      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>
>      |                          Prefix                               ~
>
>      ~                                                               |
>
>      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>
>
>
>                        Figure 2: NLRI with One Label
>
>
>
> We would like to  propose the SDWAN Instance ID being encoded in the Label
> field as follows when SDWAN SAFI (=74 allocated by IANA) is used,:
>
>
>
>       0                   1                   2                   3
>
>       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
>
>      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>
>      |    Length     |      SDWAN Instance ID (Label)        |Rsrv |S|
>
>      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>
>      |                          Prefix                               ~
>
>      ~                                                               |
>
>      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>
>
>
>                         NLRI with SDWAN Instance ID.
>
>
>
> Greatly appreciate any comments or other suggestions..
>
>
>
> Thank you,
>
> Linda Dunbar
>
>
>
> *From:* Huaimo Chen <[e-mail]>
> *Sent:* Monday, March 23, 2020 9:14 AM
> *To:* Linda Dunbar <[e-mail]>; [e-mail]
> *Cc:* [e-mail]
> *Subject:* Re: [Idr] FW: Is there any problem of using Private AS as
> "Identifier" to differentiate SD-WAN Segmentation for
> draft-dunbar-bess-bgp-sdwan-usage?
>
>
>
> Hi Linda,
>
>
>
>     It seems that using another SAFI is a possible solution.
>
>
>
> Best Regards,
>
> Huaimo
> ------------------------------
>
> *From:* Linda Dunbar <[e-mail]>
> *Sent:* Friday, March 20, 2020 12:54 AM
> *To:* Huaimo Chen <[e-mail]>; [e-mail] <[e-mail]>
> *Cc:* [e-mail] <[e-mail]>
> *Subject:* RE: [Idr] FW: Is there any problem of using Private AS as
> "Identifier" to differentiate SD-WAN Segmentation for
> draft-dunbar-bess-bgp-sdwan-usage?
>
>
>
> Huaimo,
>
>
>
> Thank you very much for the suggestion.
>
> Do you mean using the similar approach as VPN Label carried by NLRI Path
> Attribute [RFC8277] for SDWAN Segmentation Identifier?
>
> If yes, the UPDATE message should not use the MPLS VPN SAFI (=128) to
> avoid confusion, right?
>
>
>
> Linda
>
>
>
> *From:* Huaimo Chen <[e-mail]>
> *Sent:* Thursday, March 19, 2020 6:45 PM
> *To:* Linda Dunbar <[e-mail]>; [e-mail]
> *Cc:* [e-mail]
> *Subject:* Re: [Idr] FW: Is there any problem of using Private AS as
> "Identifier" to differentiate SD-WAN Segmentation for
> draft-dunbar-bess-bgp-sdwan-usage?
>
>
>
> Hi Linda,
>
>
>
>     It seems that a label may be used as an "Identifier" to differentiate
> SD-WAN Segmentation.
>
>
>
> Best Regards,
>
> Huaimo
> ------------------------------
>
> *From:* Idr <[e-mail]> on behalf of Linda Dunbar <
> [e-mail]>
> *Sent:* Thursday, March 19, 2020 1:22 PM
> *To:* [e-mail] <[e-mail]>
> *Cc:* [e-mail] <[e-mail]>
> *Subject:* [Idr] FW: Is there any problem of using Private AS as
> "Identifier" to differentiate SD-WAN Segmentation for
> draft-dunbar-bess-bgp-sdwan-usage?
>
>
>
> BGP Experts,
>
>
>
> Do you know if  there is any problem of using  Private AS as  "Identifier"
> to differentiate SD-WAN Segmentation? Here is the discussion in BESS WG.
> Want to get IDR WG feedbacks for this question.
>
>
>
> Thank you.
>
> Linda
>
>
>
> *From:* Linda Dunbar
> *Sent:* Thursday, March 19, 2020 11:54 AM
> *To:* Najem, Basil <[e-mail]>; [e-mail]
> *Cc:* [e-mail]
> *Subject:* Is there any problem of using Private AS as "Identifier" to
> differentiate SD-WAN Segmentation for draft-dunbar-bess-bgp-sdwan-usage?
>
>
>
> Based on Basil’s comment on needing an identifier to differentiate SDWAN
> instances, I added a section to  draft-dunbar-bess-bgp-sdwan-usage . Want
> to hear people’s feedback.
>
>
> 3.1    Requirements 3.1.1Supporting Multiple SDWAN Segmentations
>
> The term “network segmentation” is used extensively in SDWAN deployment.
> In general (and in this document), the “Network Segmentation” is referring
> to the process of dividing the network into logical sub-networks using
> isolation techniques on a forwarding device such as a switch, router, or
> firewall. For a homogeneous network, such as MPLS VPN or Layer 2 network,
> VRF or VLAN are used to separate network segments.
>
> As SDWAN is an overlay network arching over multiple types of networks, it
> is important to have distinct identifiers to differentiate SDWAN network
> instances (or segmentations). When different SDWAN network segments do not
> have their own assigned AS numbers, a very easy way is to use Private AS
> numbers, in the range of 64512 to 65535, to differentiate different SDWAN
> segmentations.. When using BGP to control the SDWAN networks, the Private
> AS numbers are carried by the BGP UPDATE messages to their corresponding
> RRs.
>
>
>
> Greatly appreciate any feedback on this description.
>
>
>
> Is there any scenario that Private AS cannot be used?
>
>
>
> Thank you very much.
>
>
>
> Linda Dunbar
>
>
>
> *From:* Najem, Basil <[e-mail]>
> *Sent:* Friday, February 7, 2020 3:02 PM
> *To:* Linda Dunbar <[e-mail]>; [e-mail]
> *Cc:* [e-mail]
> *Subject:* RE: solicit feedback on draft-dunbar-bess-bgp-sdwan-usage
> description of using BGP UPDATE messages to achieve SD-WAN Application
> Based Segmentation
>
>
>
>
>
>
>
> Hi Linda;
>
>
>
> The SD-WAN Segment is part of the SD-WAN fabric; in other words, there
> could be more than one Segment over a single underlay depending on the
> design and the business requirements.
>
>
>
> Each Segment represents a single and an isolated L3 domain; therefore, I
> suggested that we may need to include the Segment ID in the BGP update
> messages in order to identify and build the routing the table for each
> Segment (based on the Segment ID).
>
>
>
> Hope this helps.
>
>
>
> Regards;
>
>
>
> Basil
>
>
>
>
>
> *From:* Linda Dunbar <[e-mail]>
> *Sent:* February-03-20 10:40 AM
> *To:* Najem, Basil <[e-mail]>; [e-mail]
> *Cc:* [e-mail]
> *Subject:* [EXT]RE: solicit feedback on draft-dunbar-bess-bgp-sdwan-usage
> description of using BGP UPDATE messages to achieve SD-WAN Application
> Based Segmentation
>
>
>
> Basil,
>
>
>
> Thank you very much for the comments.
>
> Your suggested wording change will be incorporated in the next revision.
>
>
>
> As for your suggestion of Segment and Segment ID of a SDWAN node (to be
> included in the BGP UPDATE), does the “Segment” mean the different
> Underlay?
>
> In the figure below, C-PE1 has 3 WAN ports: 2 to MPLS network and 1 to
> Public Internet.
>
> Do you mean C-PE1 has 3 WAN “segments”?
>
> If not, can you elaborate more?
>
>
>
>
>
>
>
> Thanks, Linda
>
>
>
> *From:* Najem, Basil <[e-mail]>
> *Sent:* Sunday, February 02, 2020 5:48 PM
> *To:* Linda Dunbar <[e-mail]>; [e-mail]
> *Cc:* [e-mail]
> *Subject:* RE: solicit feedback on draft-dunbar-bess-bgp-sdwan-usage
> description of using BGP UPDATE messages to achieve SD-WAN Application
> Based Segmentation
>
>
>
>
>
> Hello Linda;
>
>
>
> I haven’t gone through the entire document; however, I have the following
> quick comments
>
>
>
>    1. Regarding the following paragraph:
>
>
>
> 1.       Augment of transport, which refers to utilizing overlay paths
> over different underlay networks. Very often there are multiple parallel
> overlay paths between any two SDWAN edges, some of which are private
> networks over which traffic can traverse without encryption, others require
> encryption, e.g. over untrusted public networks.
>
>
>
> The traffic that traverses the privet networks can be either encrypted or
> unecrypted (in other words, the assumption that the traffic is NOT
> encrypted is not always correct). I would change the parpagaph to the
> following (for clarity):
>
>
>
> 1.       Augment of transport, which refers to utilizing overlay paths
> over different underlay networks. Very often there are multiple parallel
> overlay paths between any two SDWAN edges, some of which are private
> networks over which traffic can traverse with or without encryption,
> others require encryption, e.g. over untrusted public networks.
>
>
>
>
>
>    1. Another thing that we need to discuss is the Segment ID; each
>    Segment (at the SD-WAN Edge) MUST have an ID. The SD-WAN Policy will map
>    the Application Flow to the Segment. Since the Segment is a “routing
>    domain”, the BGP update will be exchanged with the memebers of a particular
>    Segment.
>
>
>
> As such: Should we include the Segment ID as an attribute in the BGP
> update messages? Perhaps we need to further discuss this in details.
>
>
>
> Any feedback is welcomed and it’s highly appreciated.
>
>
>
> Regards;
>
>
>
> Basil
>
>
>
>
>
> *From:* Linda Dunbar <[e-mail]>
> *Sent:* January-31-20 5:17 PM
> *To:* [e-mail]
> *Cc:* [e-mail]
> *Subject:* [EXT]solicit feedback on draft-dunbar-bess-bgp-sdwan-usage
> description of using BGP UPDATE messages to achieve SD-WAN Application
> Based Segmentation
>
>
>
> BESS participants:
>
>
>
> “SDWAN” networks is characterized by:
>
> 1.       Augment of transport, which refers to utilizing overlay paths
> over different underlay networks. Very often there are multiple parallel
> overlay paths between any two SDWAN edges, some of which are private
> networks over which traffic can traverse without encryption, others require
> encryption, e.g. over untrusted public networks.
>
> 2.       Enable direct Internet access from remote sites, instead hauling
> all traffic to Corporate HQ for centralized policy control.
>
> 3.       Some traffic are routed based on application IDs instead of
> based on destination IP addresses.
>
>
>
>
>
> https://datatracker.ietf.org/doc/draft-dunbar-bess-bgp-sdwan-usage/
> <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fdraft-dunbar-bess-bgp-sdwan-usage%2F&data=02%7C01%7Clinda.dunbar%40futurewei.com%7C6fce142531214362ed4c08d7cf6044aa%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637205884697250108&sdata=SYcw4ORJcayiaqYuWRTUZi5zmv25X3b%2FBVm5TW0yhgg%3D&reserved=0>
> describes examples of using BGP UPDATE messages to achieve the SDWAN
> Application Based Segmentation,  assuming that the applications are
> assigned with unique IP addresses.
>
> In the Figure below, the following BGP Updates can be advertised to ensure
> that Payment Application only communicates with the Payment Gateway:
>
>
>
>
>
> BGP UPDATE #1 from C-PE2 to RR for the RED P2P topology (only propagated
> to Payment GW node:
>
> -        MP-NLRI Path Attribute:
>
>    - 30.1.1.x/24
>
> -        Tunnel Encap Path Attribute
>
>    - IPsec Attributes for PaymentGW ->C-PE2
>
>
>
> BGP UPDATE #2 from C-PE2 to RR for the routes to be reached by Purple:
>
> -        MP-NLRI Path Attribute:
>
>    - 10.1.x.x
>          - 12.4.x.x
>
> -        TunnelEncap Path Attribute:
>
>    - Any node to C-PE2
>
>
>
>
>
> Your feedback is greatly appreciated.
>
>
>
> Thank you very much.
>
>
>
> Linda Dunbar
> ------------------------------
>
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