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

[Gyan Mishra <[e-mail]>]

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*