Hi Fanghong,

My understanding of the main problem that is pointed out in your draft is that 
the "source-as" field cannot hold an IPv6 address that is required for 
non-segmented tunnels in case of IPv6 infrastructure.
The draft I referred to also pointed out that problem, and gave a solution 
(that also has other benefits) that obsoletes the requirement of encoding that 
IPv6 address.

That's why I think the (main) problem in your draft is already (better) 
addressed.

Upon further reading of your draft, I realized you also talked about another 
problem:


   In [RFC7716<https://datatracker.ietf.org/doc/html/rfc7716>], zero RD is 
introduced in BGP MVPN NLRIs to enable

   Global Table Multicast service in provider's networks.  In IPv6

   infrastructure networks, Leaf PEs cannot send two distinct

   C-multicast route to two individual upstream root PEs for selctive

   forwarding, because the RD of the two roots is the same.

That does not seem to be specific to IP6 though - we have the same problem with 
IPv4, and that's why RFC 7716 has "2.3.4.  Why SFS Does Not Apply to GTM".
The simple solution to that problem is not using SFS, and if it is desired to 
target c-multicast routes to different upstream PEs (e.g. for live-live 
redundance), we could enhance the 7716 procedures to allow non-zero RDs even 
for GTM. That does not need to change the c-mcast format (as RD is supposed to 
be treated as opaque info).

You mentioned problem with ADD-PATH. Not sure if why ADD-PATH came into the 
picture at all. RFC 7716 mentioned ADD-PATH but it is meant to say that even 
ADD-PATH would not solve the SFS problem.

Thanks.
Jeffrey



Juniper Business Use Only
From: duanfanghong <[email protected]>
Sent: Monday, May 30, 2022 2:32 AM
To: Jeffrey (Zhaohui) Zhang <[email protected]>; [email protected]
Cc: Xiejingrong (Jingrong) <[email protected]>; Gengxuesong (Geng Xuesong) 
<[email protected]>; Wangheng (MCAST, P&S) <[email protected]>
Subject: RE: [bess] A new draft for MVPN in IPv6-only network.

[External Email. Be cautious of content]

Hi Jeffrey,

I have read your draft carefully, as you mentioned in this draft, it is a less 
optimal solution for PE to PE C-Multicast signaling.

In the draft I just published, we describe IPv6-only infrastructure and 
dual-stack infrastructure issues and solutions for regular option B scenario in 
RFC 6514. So, both the scenario and solution are different from the one you 
published.

Thanks.
Fanghong.

From: Jeffrey (Zhaohui) Zhang [mailto:[email protected]]
Sent: Thursday, May 26, 2022 10:23 PM
To: duanfanghong <[email protected]<mailto:[email protected]>>; 
[email protected]<mailto:[email protected]>
Cc: Xiejingrong (Jingrong) 
<[email protected]<mailto:[email protected]>>; Gengxuesong (Geng 
Xuesong) <[email protected]<mailto:[email protected]>>; Wangheng 
(MCAST, P&S) <[email protected]<mailto:[email protected]>>
Subject: RE: [bess] A new draft for MVPN in IPv6-only network.

Hi Fanghong,

It seems that 
https://datatracker.ietf.org/doc/html/draft-zzhang-bess-mvpn-evpn-cmcast-enhancements-01#section-1.3<https://urldefense.com/v3/__https:/datatracker.ietf.org/doc/html/draft-zzhang-bess-mvpn-evpn-cmcast-enhancements-01*section-1.3__;Iw!!NEt6yMaO-gk!An361zOjmlWoNMSf73DSUaS8_rgACyWhpJqXDXIsOskU1Mu_2aAJvWLQcqzYMgIYjZ0i9ZWt3JEeKLEWNckNoq6_VOuxU5Iz$>
 talked about the problems and a more general solution.

That draft also has other enhancements considerations. It has stalled but looks 
like we should get it going.

Thanks.
Jeffrey



Juniper Business Use Only
From: BESS <[email protected]<mailto:[email protected]>> On Behalf Of 
duanfanghong
Sent: Tuesday, May 24, 2022 8:24 AM
To: [email protected]<mailto:[email protected]>
Cc: Xiejingrong (Jingrong) 
<[email protected]<mailto:[email protected]>>; Gengxuesong (Geng 
Xuesong) <[email protected]<mailto:[email protected]>>; Wangheng 
(MCAST, P&S) <[email protected]<mailto:[email protected]>>
Subject: [bess] A new draft for MVPN in IPv6-only network.

[External Email. Be cautious of content]

Hi All,

  MVPN(RFC 6513/RFC 6514/RFC 6515) faces some problems in IPv6-only networks, 
especially in the non-segmented inter-AS scenario and IPv4 to IPv6 migration 
scenario.
  We have published a new draft 
https://datatracker.ietf.org/doc/draft-duan-bess-mvpn-ipv6-infras/<https://urldefense.com/v3/__https:/datatracker.ietf.org/doc/draft-duan-bess-mvpn-ipv6-infras/__;!!NEt6yMaO-gk!An361zOjmlWoNMSf73DSUaS8_rgACyWhpJqXDXIsOskU1Mu_2aAJvWLQcqzYMgIYjZ0i9ZWt3JEeKLEWNckNoq6_VHqmJjHC$>,
 aiming to solve these problems.

  Please provide your valuable comments and help evolving it further.

  Thanks.

Regards,
Fanghong
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