Re: [Idr] [bess] Suggestion on v4-only/v6-only drafts

[Gyan Mishra <[e-mail]>]

Hi Igor

Pleas see in-line Gyan3>

On Sun, Nov 13, 2022 at 11:48 AM Igor Malyushkin <[e-mail]>
wrote:

> Hi Gyan, my inline is below.
>
> вс, 13 нояб. 2022 г. в 10:29, Gyan Mishra <[e-mail]>:
>
>>
>> Hi Igor
>>
>> Please see in-line Gyan2>
>>
>> On Sat, Nov 12, 2022 at 7:44 PM Igor Malyushkin <[e-mail]>
>> wrote:
>>
>>> Hi Gyan, please see the inline.
>>>
>>> вс, 13 нояб. 2022 г. в 01:39, Gyan Mishra <[e-mail]>:
>>>
>>>> Hi Igor
>>>>
>>>> Thank you for your comments
>>>>
>>>> Understood that 4PE has been implemented by most vendors, however a
>>>> standards specification has not been written till now and standardization
>>>> of this draft would ensure interoperability as many operators have mix
>>>> vendor environments.
>>>>
>>>> Responses in-line
>>>>
>>>> Thanks
>>>>
>>>> On Sat, Nov 12, 2022 at 5:31 PM Igor Malyushkin <[e-mail]>
>>>> wrote:
>>>>
>>>>> Hi gents,
>>>>>
>>>>> I found this conversation curious and started reading the document
>>>>> (draft-mishra-idr-v4-islands-v6-core-4pe-02). First, I skipped the section
>>>>> about SRv6 because I'm not good at this technology. Maybe the deal is this
>>>>> section because I couldn't find anything new in the rest of the document to
>>>>> put it into the Standard Track category. It more looks like a list of best
>>>>> practices to fire up 4PE in the network.
>>>>>
>>>>
>>>>    Gyan> The reason for standardization is to ensure that the process
>>>> and procedures implemented by each vendor is the same to ensure
>>>> interoperability
>>>>
>>>  [IM] Could you please describe the process and the procedures? It's
>>> not clear to me.
>>>
>>
>> Gyan2> 4PE procedure is described in detail in section 3 and 4.
>>
>
>> Spreading the reachability over BGP with a different next-hop family is
>>> well written in 8950.
>>>
>>
>> Gyan2>  Here we are not just spreading the reachability over different
>> next hops per RFC 8950.
>> There is more to 4PE then just the transport tunnel.
>>
> [IM2] I consider the 4PE and 6PE as the things that help us interconnect
> IPv4/6 islands over the IPv6/4 core. You consider them as things of
> interconnecting IPv4/6 islands over the IPv6/4 core *via labeled unicast*.
> This is not the only way.
>

   Gyan3> I believe your concerns are addressed in section 7 inter-as
options

>
>> Signaling and pointing tunnels toward the next hops aren't new too.
>>>
>>
>> Gyan2> There is nothing special about the  IPv6 transport LSP towards the
>> egress next hops as that’s is typical to carry and service.  What is
>> critical is the 2 level label stack.
>>
>
>> Other things look like the best practices that don't alter any protocol
>>> or technology. Can you highlight what exactly requires standardization?
>>>
>>
>> Gyan2> What we are standardizing with the 4PE procedure is a two level
>> label stack that you have the  topmost transport IPv6 LSP signaling the
>> egress next hop to carry the service label IPv4 LU prefixes so all the IPv4
>> prefixes must have a label binding.
>>
> [IM2] I've read your draft and understand it well. I disagree that we need
> to use ONLY IPv4 LU prefixes and that ALL the IPv4 prefixes MUST have a
> label binding. It's entirely wrong and harmful. What you described in this
> draft is the one OPTION to do the interconnection of 4PE islands over IPv6
> transport. There are others.
>

   Gyan3> The draft describes in section 3 and 4 intra-as option within a
single domain and it talks to iBGP PE-RR peering and use of IPV4 LU for the
PE-CE IPv4 prefixes. Section 7 describes inter-as options and there it does
have Option-A back to back CE scenario where the IPv4 prefixes are
unlabeled and uses 1/1 IPv4 Unicast as you have described and desire. Does
that address your concerns.

>
>> E.g., in the Security section, you state "The extensions defined in this
>>> document...", which extensions?
>>>
>>>>
>>    Gyan2> Sorry that was in error, I will fix in the next revision.  This
>> specification uses existing mechanisms with a new procedure for 4PE.
>>
>>>
>>>> Of course, 4PE is already a well-known design pattern that has been
>>>>> implemented in lots of network OS and moreover implemented in production
>>>>> networks.
>>>>>
>>>>
>>>> Gyan> 4PE is well known however it has not been standardized so this
>>>> would make it standard across all vendor implementations
>>>>
>>> [IM] It depends on the goal of this "standard". 4PE just as 6PE is the
>>> design-matter thing, we can implement 6PE in several ways with the standard
>>> building blocks (8950 and other things).
>>>
>>>>
>>     Gyan2> The goal of the standard is to have a set procedure for 4PE
>> that would be standardized.
>>
> I disagree that 6PE RFC 4798 is a “design-matter” thing as it is standards
>> track document
>>
> and if it were a “design-matter” thing there would have been no need for
>> RFC 4798.
>>
> I don’t know of any vendor that implements 6PE in several ways.
>>
> [IM2] I know at least two of them: Juniper and Nokia. Moreover, we have
> tested interop for that and designed it for the Customer.
>

    Gyan3>  Ok.  In the interop test was it for 6PE or 4PE? This seems to
be a corner case that you were trying to address.  I don’t known if that
needs to be documented in the draft.

>
> There has only been one method to implement 6PE and that is following RFC
>> 4798 which all implementations use SAFI 4 IPv6 labeled unicast 2/4.
>>
>> Cisco
>>
>> https://community.cisco.com/t5/service-providers-knowledge-base/6pe-with-ibgp-ios-xr-example/ta-p/3149743
>>
>> Juniper
>>
>> https://www.juniper.net/documentation/us/en/software/junos/mpls/topics/topic-map/ipv6-o-ipv4-tunnels.html
>>
>> Nokia
>>
>> https://infocenter.nokia.com/public/7750SR225R1A/index.jsp?topic=%2Fcom.nokia.Router_Configuration_Guide%2Fipv6_provider_e-d10e2482.html
>>
>> Arista
>>
>> https://www.arista.com/en/um-eos/eos-border-gateway-protocol-bgp?searchword=eos%20section%2035%204%20is%20is%20commands
>>
>> Please sent me a link of proof of a single vendor that has implemented
>> 6PE using IPv6 unicast?
>>
> [IM2] I'm sorry but I think we have to use vendor-neutral terminology and
> describe any technology step-by-step without links to anywhere except the
> Standards. You can ask your vendor how to advertise IPv6 labeled unicast
> over IPv4 iBGP session with IPv4-mapped addresses, and how to resolve these
> addresses to LSPs. This works well.
>

    Gyan3>  As the debate is about 6PE implementations and I wanted to
share concrete implementation documentation of 6PE standards that the
documents show there IPv6 labeled unicast is used

>
>>>> Personally, I'm not against having a BCP document that combines
>>>>> everything about 4PE together if the authors want to perpetuate
>>>>> the abbreviation.
>>>>>
>>>>
>>>> Gyan> I think the process and procedures can be standardized with the
>>>> normative language as written to ensure vendor interoperability.  Existing
>>>> mechanisms are used however the draft defines procedures to be followed and
>>>> that is what would be standardized.
>>>>
>>> [IM] Again, I believe we should clarify the point where interop issues
>>> can arise and then solve them for the document that describes the mechanism
>>> that is the root of the problem.
>>>
>>
>>     Gyan2> You have hit right on the interoperability issue where you
>> have brought up that it’s a design matter to use SAFI 4 IPv4 LU and have
>> the choice to use SAFI 1 IPv4 Unicast.  So that is the crux of 4PE that the
>> IPv4 prefixes must be labeled.  That’s a main reason for standardization
>> that the IPV4 LU must be used.
>>
>
>>>>>
>>>>> The second thing is about wording/writing. I don't want to seem rude
>>>>> or something but it was challenging for me to read the document. I
>>>>> believe it should be rewritten in a clearer way.
>>>>>
>>>>
>>>> Gyan> No worries, I can work with the authors to clean up the writing
>>>> and thank you for the feedback.
>>>>
>>> [IM] Thanks!
>>>
>>>>
>>>>>
>>>>> Talking about the 4PE and after reading this document I disagree with
>>>>> the idea to use LU as the only way to spread reachability (actually I
>>>>> prefer almost not to use it for this task it better suits LSP signaling).
>>>>>
>>>>
>>>> Gyan>  The reason for the  BGP LU label binding of all the IPV4
>>>> prefixes tunneled over the core is for the PHP node exposing the native
>>>> IPv4 packet which would not have the EXP marking PHB scheduling.
>>>>
>>> [IM] This is possible without the distribution of IPv4 routes with
>>> labels. I can distribute just a single route toward their next hop which is
>>> the best thing BGP-LU does. The label stack would have two labels.
>>>
>>
>> Gyan2> I am not following.  BGP LU allocates and advertises all the
>> prefixes with labels.  When you distribute a single route as SAFI 1 it does
>> not have a label but if you distribute a SAFI 4 route it does have a label
>> and is LU.
>>
> [IM2] By your draft I have to advertise all prefixes received from an IPv4
> PE-CE session via internal BGP sessions as IPv4 labeled prefixes and use
> the IPv6 address of the PE as NH. Instead, I can advertise these prefixes
> as IPv4 unicast (1/1) without the next hop changing. And for the original
> next hop address (CE address) advertise an IPv4 labeled unicast route with
> the router's IPv6 address. In the end, there will be lots of unlabeled
> routes and a single labeled (toward the NH). Thus we separate the
> reachability and the BGP LSP signaling. Ingress PE will use two tunnels:
> inner will be BGP LSP (IPv4 LU route with IPv6 next hop address) and outer
> will be LDP/RSVP LSP toward the next hop address. So there will be the
> indirection of the IPv4 unicast route (with IPv4 NH) over the IPv4 labeled
> unicast route (with IPv6 NH) and some underlay LSP at the top. This scheme
> gives me the ability to react on the PE-CE link flaps and benefit from PIC.
> In your scheme, I have to wait for the global convergence of IPv4 labeled
> unicast (if the PE is alive). In both schemes, there will be two labels in
> the stack. Also, I still don't understand how your scheme brings us EPE.
> Another option is to advertise IPv4 unicast routes with the IPv6 next hop
> and signal BGP LSP for that address (via BGP IPv6 labeled unicast route
> with arbitrary labels) and then resolve it BGP LSP over LDP/RSVP/etc. Still
> two labels in the stack.
> As you can see there are several ways to interconnect IPv4 islands. All of
> them have some pluses and minuses. That's why I said -- this is a design
> matter.
>
>

Gyan3>Section 7 goes over inter-as options of 4PE and in option-a which
uses IPv4 unicast unlabeled prefixes.  As you desire. Does that section
address what you have described above which sounds like inter-as scenario.
Section 3 and 4 of the draft addresses intra-as PE-RR peering using IPv4 LU.

>
>>>
>>>> This is exactly what is done in 6PE as it as well uses BGP-LU for the
>>>> same reason labeling all the IPv6 prefixes tunneled.  This is a good
>>>> example and reason for standardization.
>>>>
>>> [IM] 6PE can be done without labeled unicast at all if talk about the
>>> interconnection of IPv6 islands over IPv4 core. That's why I said -- this
>>> is a design matter.
>>>
>>
>> Gyan2> I don’t see how that’s possible without breaking QOS EXP PHB
>> scheduling on the PHP egress PE.  You argument is the reason for
>> standardization.
>>
> [IM2] Just don't use PHP?
>
>
>> If we go down the path you are describing that this is a “design thing”
>> and implement however you like we would have all sorts of interoperability
>> issues.
>>
>
>>>
>>>> If one vendor labeled the tunneled prefixes and another vendor
>>>> implementation did not we would run into issues.
>>>>
>>> [IM] And this is a good thing (I mean having several ways to make things
>>> done). You should require your vendor to support both options or don't buy
>>> gear from a vendor who can't do it.
>>>
>>
>> Gyan2> As I said your argument for keeping things open and a “design
>> thing” is a reason for standardization as was done with 6PE and you can see
>> all vendors have implemented exactly that using IPv6 LU and not IPv6
>> Unicast to connect IPv6 islands over an IPv4 core.
>>
> [IM2] I disagree. You are trying to restrict me to do the 4PE in your
> preferred way.
>

    Gyan3> As I stated above let me know if section 7 inter-as options
addresses your concerns as it is inclusive of inter-as option-a which uses
1/1 IPv4 Unicast as you would like for your use case

>
>>>
>>>> We have not had at least in North America and Europe many networks that
>>>> have migrated to IPv6 core so have not seen interoperability issues however
>>>> as more operators now start to migrate to an IPV6 data plane ..MPLS,
>>>> SR-MPLS, SRV6 we could have issues so I think it’s important to get this
>>>> standardized.
>>>>
>>>  [IM] Yes we ran over lots of such issues too but all of them were
>>> pieces of some concrete technology.
>>>
>>>>
>>>> This approach governs me to always bind any reachability to a PE but
>>>>> not to a CE.
>>>>>
>>>>
>>>> Gyan> Yes for an important reason for the PHP node POP and forwarding
>>>> native IPv4 packet and breaking EXP scheduling on the last hop to the
>>>> egress PE
>>>>
>>>  [IM] As I pointed out previously there is no difference if we don't
>>> distribute reachability without labels and if we use BGP tunnels to NH over
>>> underlay tunnels (RSVP, LDP, whatever).
>>>
>>>>
>>>> How can I implement EPE this way?
>>>>>
>>>>
>>>> Gyan> You can still implement EPE with BGP-LU SR EPE or EPE w/o SR
>>>>
>>> [IM] Could you please describe the case without SR?
>>>
>>>>
>>    Gyan2> With EPE the ingress PE signals the egress next hop and which
>> hop to be used via centralized controller PCE / BGP-LS and can be done
>> using RSVP-TE or SR for EPE
>>
>> Juniper example
>>
>>
>> https://www.juniper.net/documentation/us/en/software/junos/bgp/topics/topic-map/bgp-egress-traffic-engineering.html
>>
> [IM2] Well. I hoped you can describe the way applied to your solution. I
> can find any documentation for the current solutions on my own, thank you.
>

Gyan3> EPE acts at the transport layer ingress signaling to the egress exit
point discreetly EPE with BGP-LU or EPE with SR.  As EPE is acting at the
transport layer topmost label steering to the desired egress exit point
that is independent of the tunneled IPv4 prefixes being labeled or not
labeled.  So I think EPE would work just fine with the IPv4 prefixes
labeled.

>
>
>>
>>>> What if I want to advertise IPv4 prefixes with vanilla IPv4 (1/1) with
>>>>> IPv4-encoded NH (let's say with the CE address) and propagate this NH as
>>>>> IPv4 LU with the IPv6 NH?
>>>>>
>>>>
>>>> Sure that would work fine.  That is exactly what is stated in the draft
>>>> as the process for 4PE.
>>>>
>>>  [IM] Your document requires me to use BGP-LU for IPv4 reachability
>>> dissemination, I don't see why I need to resolve an IPv4 LU route over
>>> another IPv4 LU.
>>>
>>
>>    Gyan> I think you are getting 6PE and 4PE mixed up.  With 6PE you have
>> a IPv4 transport LSP tunnel IPv4 next hop and IPv6 prefixes distributed as
>> labeled within the tunnel.  With 4PE you have a IPv6 transport LSP tunnel
>> IPv6 next hop and IP4 prefixes distributed as labeled within the tunnel.
>>
> [IM2] I've described some cases above, please see them.
>

   Gyan3> Please look at section 3 and see if that addresses your concerns

>
>>>> I see a lot of "MUST" preventing me from doing so.
>>>>>
>>>>
>>>>    Where ? Please quote the line or paragraph
>>>>
>>> [IM] Let's dig into the third section.
>>> 1. *Exchange IPv4 reachability information* among 4PE Ingress and
>>> Egress PE routers using MP- BGP [RFC2545
>>> <https://www.ietf.org/archive/id/draft-mishra-idr-v4-islands-v6-core-4pe-02.html#RFC2545>
>>> ]:
>>> In doing so, the 4PE routers convey *their IPv6 address* as the BGP
>>> Next Hop for the advertised IPv4 prefixes.
>>> [IM] What if I don't have any IPv6 addresses on PE-CE interfaces and I
>>> don't want to use the loopback IPv6 address?
>>>
>>
>>     Gyan2> The PE-CE interface in this 4PE use case is IPv4 islands over
>> an IPv6 core so the Island CEs are IPv4 attached PE-CE.  So here we are
>> conveying the IPv6 address which is the ingress and egress PE loopback to
>> build the transport IPv6 LSP to advertise the IPv4 LU prefixes being
>> tunneled.
>>
> [IM2] And that is the problem with your approach. Also, see above.
>
>> The Subsequence Address Family Identifier (SAFI) used in MP-BGP *MUST be
>>> the "label" SAFI (value 4)* as defined in [RFC8277
>>> <https://www.ietf.org/archive/id/draft-mishra-idr-v4-islands-v6-core-4pe-02.html#RFC8277>
>>> ] called BGP Labeled Unicast (BGP-LU).
>>> [IM] Why can't it be SAFI 1? Why MUST I always use SAFI 4? I don't want.
>>> (Again, I still can have two labels in the stack).
>>>
>>
>>    Gyan2> How would you have 2 labels in the label stack if you use SAFI
>> 1 1/1 IPv4 Unicast as that would be “native IPv4 packets” non labeled no
>> MPLS shim. So as I said before and the reason for the standardization is
>> that if you don’t label the IPv4 prefixes from the IPv4 island being
>> tunneled over the IPv6 LSP then on the PHP node when the transport label is
>> popped implicit null value 3, the native IPv4 packet is exposed and is
>> forwarded from the egress P PHP node w/ PHB scheduling broken as EXP match
>> cannot occur without the IPv4 prefixes being labeled IPv4 LU.  That is a
>> requirement for 4PE to work w/o breaking QOS EXP scheduling and is the
>> procedure that must be followed for any 4PE implementations.
>>
>> So It’s not just breaking QOS EXP scheduling as once the PHP POP  happens
>> on the PHP node for 6PE the native IPv6 packet is exposed and that cannot
>> be forwarded as the core is a per standard design following RFC 5545
>> Softwire mesh framework a single protocol IPv4 only core so the IPv6 packet
>> is dropped and cannot be forwarded.
>>
>> As well for 4PE It’s not just breaking QOS EXP scheduling as once the
>> PHP POP  happens on the PHP node the show stopper deal breakers is that
>>  the native IPv4 packet is exposed and that cannot be forwarded as the core
>> is a per standard design following RFC 5545 Softwire mesh framework a
>> single protocol IPv6 only core so the then the IPV4 packet is dropped and
>> cannot be forwarded.
>>
>> As well is discussed in the draft even if IPv6 explicit null is used Pipe
>> mode RFC 3270 MPLS Diffserv, explicit null label cannot carry a native IPv4
>> packet SAFI 1 and would be dropped and would have to be LU labeled IPv4
>> packets or the packets would get dropped.  In a global table routing
>> scenario IPv4 packets tunneled over an IPv4 core don’t have to be labeled
>> as it will break QOS EXP on the PHP node but in this case the native IPv4
>> packet is exposed and can still be forwarded and not dropped as all the
>> core P nodes are IPv4 enabled core, as with the 6PE encapsulation mismatch
>> and resulting IPv6 packets being dropped.  Similarly In a global table
>> routing scenario IPv6 packets tunneled over an IPv6 core don’t have to be
>> labeled as it will break QOS EXP on the PHP node but in this case the
>> native IPv6 packet is exposed and can still be forwarded and not dropped as
>> all the P nodes are IPv6 enabled core, as with the 4PE encapsulation
>> mismatch and resulting IPv4 packets being dropped.  The “design thing”
>> scenario does come into play here with what I described above where the CE
>> packet protocol matches the core protocol then you have the option to label
>> or not label the packets.  Some vendors have the ability to match on both
>> dscp and exp so even when the PHP POP and forward happens on the PHP node
>> the router can schedule based on DSCP and if the label is present switch
>> gears and schedule match on EXP.  So based on what is supported in the
>> protocol matching scenario can decide to label or not label the customer
>> traffic ingressing the core.
>>
>> ***I hope what I said above really helps clarify and cleans up any
>> confusion and I can as well make these points more clear in the draft***
>>
>> So to reiterate the show stopper and why the packets being tunneled over
>> the core must be labeled must have the MPLS shim for label switching and
>> forwarding is the protocol mismatch scenario that happens when the native
>> packet gets exposed after the PHP POP and the P / PE all core nodes are
>> IPv6 only - IPv6 only core for 4PE scenario and IPv4 only - IPV4 only core
>> for 6PE scenario.
>>
>>
>> That's why I said that we don't have to have the exact way to do things.
>>> I agree that is good to describe the necessity of having two labels and why
>>> but I don't think that it's the standard matter how I reach this goal,
>>> which family I will use, and so on.
>>>
>>
>> Gyan2> As I said your argument for SAFI 1 is the main reason why we need
>> to have 4PE procedure to use SAFI 4 IPv4 labeled unicast so that all
>> implementations of 4PE must follow the standard specification for
>> interoperability.
>>
>>>
>>>
>>>
>>>> Thank you
>>>>
>>>>>
>>>>>
>>>>> сб, 12 нояб. 2022 г. в 02:08, Gyan Mishra <[e-mail]>:
>>>>>
>>>>>>
>>>>>> Thanks Robert for your feedback on the draft.
>>>>>>
>>>>>> Dear IDR
>>>>>>
>>>>>> Please review the draft and provide feedback.
>>>>>>
>>>>>> Thank you
>>>>>>
>>>>>> Gyan
>>>>>>
>>>>>> On Fri, Nov 11, 2022 at 6:46 PM Robert Raszuk <[e-mail]>
>>>>>> wrote:
>>>>>>
>>>>>>> Gyan,
>>>>>>>
>>>>>>> Returning today from London I did read the draft. It's a great
>>>>>>> example of how IETF documents should *NOT* be written. 47 references says
>>>>>>> it all. You are mixing pieces from completely different areas all in one
>>>>>>> place.
>>>>>>>
>>>>>>> Indeed I encourage everyone to read this draft and submit an opinion
>>>>>>> to the list before WG takes any action on it.
>>>>>>>
>>>>>>> > You mean IPv6 mapped IPv4 address.
>>>>>>>
>>>>>>> No, I meant what I wrote.
>>>>>>>
>>>>>>> Kind regards,
>>>>>>> R.
>>>>>>>
>>>>>>>
>>>>>>> On Sat, Nov 12, 2022 at 12:13 AM Gyan Mishra <[e-mail]>
>>>>>>> wrote:
>>>>>>>
>>>>>>>> Robert
>>>>>>>>
>>>>>>>> On Fri, Nov 11, 2022 at 4:49 PM Robert Raszuk <[e-mail]>
>>>>>>>> wrote:
>>>>>>>>
>>>>>>>>> Gyan,
>>>>>>>>>
>>>>>>>>> RFC8950 is all that is required to be standardized in IDR for
>>>>>>>> connecting ipv4 sites over ipv6 core from the perspective of BGP extension
>>>>>>>> to propagate reachability in the control plane. /* Btw as stated in my
>>>>>>>> previous note even that is not needed if we would solve the requirement
>>>>>>>> using v4 mapped v6 addresses. */
>>>>>>>>
>>>>>>>>    Gyan> 4PE as well as 6PE is more then just reachability
>>>>>>>> extension next hop encoding.  Please read the draft and then provide me
>>>>>>>> some feedback as it goes over all different inter-as scenarios as well as
>>>>>>>> details requirements for 2 level label stack related BGP-LU labeled unicast
>>>>>>>> labeling binding of all the IPv4 prefixes.  As well as implicit null PHP
>>>>>>>> and explicit null case for RFC 3270 pipe mode support etc.
>>>>>>>>
>>>>>>>> You mean IPv6 mapped IPv4 address.  That has always been very
>>>>>>>> confusing for troubleshooting as the next hop should follow the core
>>>>>>>> protocol used for reachability and not the NLRI which would have been done
>>>>>>>> backwards with IPv6 mapped IPv4 address and who knows what that would
>>>>>>>> encode you look like..  for IPv4 core IPv6 NLRI over and IPv4 next hop is
>>>>>>>> IPv4 mapped IPv6 address ::FFFF:10.0.0.1.  That was one of the main reasons
>>>>>>>> for encoding  simplicity to change to IPv6 address follows the core
>>>>>>>> protocol in RFC 8950 and not use IPv6 mapped IPv4 address.  Since the
>>>>>>>> mapped address is not a legitimate address extra coding hooks need to be
>>>>>>>> done to make it routable based on the embedded PE loopback in the next hop
>>>>>>>> address.  All avoided and confusion avoided by using RFC 8950 style next
>>>>>>>> hop encoding and not using a mapped address.
>>>>>>>>
>>>>>>>>>
>>>>>>>>> > This draft also defines critical extensibility to segment
>>>>>>>>> routing SR-MPLS and SRv6 which did
>>>>>>>>> > not exist when 6PE RFC 4798 was developed.
>>>>>>>>>
>>>>>>>>> IDR does not standardize SR-MPLS nor SRv6.
>>>>>>>>>
>>>>>>>>
>>>>>>>>     Gyan> I am not standardizing SR as here just providing
>>>>>>>> extensibility of the specification to support Segment Routing.
>>>>>>>>
>>>>>>>>>
>>>>>>>>> > RFC 8950 as stated defines only  the next hop encoding and for
>>>>>>>>> example does not define
>>>>>>>>> > BGP MPLS VPN RFC 4659 AFI/SAFI 2/128 specification nor does it
>>>>>>>>> define BGP LU
>>>>>>>>> > RFC 8277 specification  AFI /SAFI 2/4….
>>>>>>>>>
>>>>>>>>> This is all defined in stated above documents.
>>>>>>>>>
>>>>>>>>
>>>>>>>>     Gyan> My point here is that AFI/SAFI 2/128 and 2/4 use RFC 8950
>>>>>>>> which only defines the next hop encoding for the AFI/SAFI and not the
>>>>>>>> specification for the AFI/SAFI and thus the RFC.  RFC 4798 6PE uses IPv4
>>>>>>>> mapped IPv6 next hop encoding which does not have a next hop encoding
>>>>>>>> specification but still does have an RFC for 6PE.  Even if a next hop
>>>>>>>> encoding standard existed, that would just be for the next hop encoding,
>>>>>>>> does not mean that a standard for 6PE is not necessary for interoperability
>>>>>>>> as is the case here.
>>>>>>>>
>>>>>>>>>
>>>>>>>>> IDR drafts focus on required protocol extensions to BGP. I do not
>>>>>>>>> see any new protocol extensions in this draft anyway.
>>>>>>>>>
>>>>>>>>
>>>>>>>> Gyan> 6PE RFC 4798 as well does not have a IANA code point
>>>>>>>> allocation for a protocol extension, however it does define a procedure and
>>>>>>>> process of how 6PE works which is why it was still standardized so ensure
>>>>>>>> interoperability between vendor implementations.  There are many more
>>>>>>>> examples as such that have
>>>>>>>>
>>>>>>>>>
>>>>>>>>> Regards,
>>>>>>>>> R.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On Fri, Nov 11, 2022 at 10:38 PM Gyan Mishra <
>>>>>>>>> [e-mail]> wrote:
>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Robert
>>>>>>>>>>
>>>>>>>>>> RFC 8950 only defines only the IPv4 NLRI over IPv6 next hop
>>>>>>>>>> encoding IANA BGP capability code point 5 that updates RFC 5549 next hop
>>>>>>>>>> encoding for SAFI 128 and 129 where the 8 byte RD set to 0 was left of the
>>>>>>>>>> next hop encoding specification.
>>>>>>>>>>
>>>>>>>>>> RFC 8950 as stated defines only  the next hop encoding and for
>>>>>>>>>> example does not define BGP MPLS VPN RFC 4659 AFI/SAFI 2/128 specification
>>>>>>>>>> nor does it define BGP LU RFC 8277 specification  AFI /SAFI 2/4….
>>>>>>>>>>
>>>>>>>>>> The next hop encoding is just component of the overall 4PE
>>>>>>>>>> specification which did exist till this draft was published.  There are
>>>>>>>>>> vendors that have implemented 4PE which may or may not even be called 4PE,
>>>>>>>>>> and this draft defines the name “4PE” and what it means form a
>>>>>>>>>> specification perspective and thus would ensure the standardization of all
>>>>>>>>>> implementations to ensure interoperability.
>>>>>>>>>>
>>>>>>>>>> As operators start migrating their core to IPv6 this does become
>>>>>>>>>> a big deal as most operators have multi vendor environments and so this
>>>>>>>>>> comes to the surface as a hot topic to ensure interoperability.
>>>>>>>>>>
>>>>>>>>>> This draft also defines critical extensibility to segment routing
>>>>>>>>>> SR-MPLS and SRv6 which did not exist when 6PE RFC 4798 was developed.
>>>>>>>>>>
>>>>>>>>>> Many Thanks
>>>>>>>>>>
>>>>>>>>>> Gyan
>>>>>>>>>>
>>>>>>>>>> On Fri, Nov 11, 2022 at 3:56 PM Robert Raszuk <[e-mail]>
>>>>>>>>>> wrote:
>>>>>>>>>>
>>>>>>>>>>> Gyan,
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>> IDR draft:
>>>>>>>>>>>>
>>>>>>>>>>>> The 4PE draft connecting IPv4 islands over an IPv6 core  over
>>>>>>>>>>>> the global table is similar in semantics to 6PE RFC 4798 which connects
>>>>>>>>>>>> IPv6 islands over an IPv4 core over the global table and the draft is
>>>>>>>>>>>> extensible to SR-MPLS and SRv6. There currently is not a standard for 4PE
>>>>>>>>>>>> so this draft would standardize 4PE for vendor  interoperability.
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Not true.
>>>>>>>>>>>
>>>>>>>>>>> Quote from RFC8950:
>>>>>>>>>>>
>>>>>>>>>>> [image: image.png]
>>>>>>>>>>>
>>>>>>>>>>> I do not see anything your draft would add to it.
>>>>>>>>>>>
>>>>>>>>>>> Cheers,
>>>>>>>>>>> R.
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> https://datatracker.ietf.org/doc/draft-mishra-idr-v4-islands-v6-core-4pe/
>>>>>>>>>>>>
>>>>>>>>>>>> BESS drafts - these drafts are completely different from IDR
>>>>>>>>>>>> 4PE draft.
>>>>>>>>>>>>
>>>>>>>>>>>> I have already combined two of the drafts into one for the
>>>>>>>>>>>> IPv4-Only PE All SAFI draft
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> https://datatracker.ietf.org/doc/draft-mishra-bess-ipv4-only-pe-design-all-safi/
>>>>>>>>>>>>
>>>>>>>>>>>> IPv6 Only PE Design BCP draft below was adopted  last year and
>>>>>>>>>>>> the new draft extensible to ALL SAFI Standards Track below I plan to
>>>>>>>>>>>> progress separately.  As one is BCP and the other Standards track I don’t
>>>>>>>>>>>> think they could be combined and even if they were combined into the super
>>>>>>>>>>>> set all SAFI that would have to go through adoption process again anyway so
>>>>>>>>>>>> I plan to keep separate.
>>>>>>>>>>>>
>>>>>>>>>>>> This draft I will queue up for adoption call.
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> https://datatracker.ietf.org/doc/draft-mishra-bess-ipv6-only-pe-design-all-safi/
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> Many Thanks
>>>>>>>>>>>>
>>>>>>>>>>>> Gyan
>>>>>>>>>>>>
>>>>>>>>>>>> On Fri, Nov 11, 2022 at 6:19 AM Ketan Talaulikar <
>>>>>>>>>>>> [e-mail]> wrote:
>>>>>>>>>>>>
>>>>>>>>>>>>> Hi Gyan,
>>>>>>>>>>>>>
>>>>>>>>>>>>> Sharing a couple of suggestions here for your 5 drafts (4 in
>>>>>>>>>>>>> BESS + 1 in IDR) as we lost time due to the audio issues:
>>>>>>>>>>>>>
>>>>>>>>>>>>> (1) put the portions to be standardized (very focussed/small
>>>>>>>>>>>>> hopefully) in one single draft and post/share with both IDR and BESS since
>>>>>>>>>>>>> you are changing NH encoding (from what I heard?)
>>>>>>>>>>>>> (2) all other informational/BCP material could be combined in
>>>>>>>>>>>>> a single draft (perhaps the existing BESS WG draft)
>>>>>>>>>>>>>
>>>>>>>>>>>>> IMHO, that would facilitate an appropriate focussed review of
>>>>>>>>>>>>> the content/proposals.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>> Ketan
>>>>>>>>>>>>>
>>>>>>>>>>>>> --
>>>>>>>>>>>>
>>>>>>>>>>>> <http://www.verizon.com/>
>>>>>>>>>>>>
>>>>>>>>>>>> *Gyan Mishra*
>>>>>>>>>>>>
>>>>>>>>>>>> *Network Solutions A**rchitect *
>>>>>>>>>>>>
>>>>>>>>>>>> *Email [e-mail] <[e-mail]>*
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> *M 301 502-1347*
>>>>>>>>>>>>
>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>> BESS mailing list
>>>>>>>>>>>> [e-mail]
>>>>>>>>>>>> https://www.ietf.org/mailman/listinfo/bess
>>>>>>>>>>>>
>>>>>>>>>>> --
>>>>>>>>>>
>>>>>>>>>> <http://www.verizon.com/>
>>>>>>>>>>
>>>>>>>>>> *Gyan Mishra*
>>>>>>>>>>
>>>>>>>>>> *Network Solutions A**rchitect *
>>>>>>>>>>
>>>>>>>>>> *Email [e-mail] <[e-mail]>*
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> *M 301 502-1347*
>>>>>>>>>>
>>>>>>>>>> --
>>>>>>>>
>>>>>>>> <http://www.verizon.com/>
>>>>>>>>
>>>>>>>> *Gyan Mishra*
>>>>>>>>
>>>>>>>> *Network Solutions A**rchitect *
>>>>>>>>
>>>>>>>> *Email [e-mail] <[e-mail]>*
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> *M 301 502-1347*
>>>>>>>>
>>>>>>>> --
>>>>>>
>>>>>> <http://www.verizon.com/>
>>>>>>
>>>>>> *Gyan Mishra*
>>>>>>
>>>>>> *Network Solutions A**rchitect *
>>>>>>
>>>>>> *Email [e-mail] <[e-mail]>*
>>>>>>
>>>>>>
>>>>>>
>>>>>> *M 301 502-1347*
>>>>>>
>>>>>> _______________________________________________
>>>>>> Idr mailing list
>>>>>> [e-mail]
>>>>>> https://www.ietf.org/mailman/listinfo/idr
>>>>>>
>>>>> --
>>>>
>>>> <http://www.verizon.com/>
>>>>
>>>> *Gyan Mishra*
>>>>
>>>> *Network Solutions A**rchitect *
>>>>
>>>> *Email [e-mail] <[e-mail]>*
>>>>
>>>>
>>>>
>>>> *M 301 502-1347*
>>>>
>>>> --
>>
>> <http://www.verizon.com/>
>>
>> *Gyan Mishra*
>>
>> *Network Solutions A**rchitect *
>>
>> *Email [e-mail] <[e-mail]>*
>>
>>
>>
>> *M 301 502-1347*
>>
>> --

<http://www.verizon.com/>

*Gyan Mishra*

*Network Solutions A**rchitect *

*Email [e-mail] <[e-mail]>*



*M 301 502-1347*