Jorge, Yubao and all,
A couple of comments.
The current version of
7432bis<https://datatracker.ietf.org/doc/html/draft-ietf-bess-rfc7432bis-07>
says that:
* Per-ES EVPN A-D routes MUST use Type 1 RDs with the Administrator field
comprising “an IP address of the PE (typically, the loopback address)”
* Per-EVI EVPN A-D routes and EVPN MAC/IP Advertisement routes advertised
by an EVPN Instance locally represented by a MAC-VRF use the RD that is
assigned to this MAC-VRF, and usage of Type 1 RD with the Administrator field
comprising “an IP address of the PE (typically, the loopback address)” is
RECOMMENDED.
RFC 2119 says that “the adjective "RECOMMENDED", mean that there may exist
valid reasons in particular circumstances to ignore a particular item, but the
full implications must be understood and carefully weighed before choosing a
different course”. Therefore, I concur with Jorge that people who decide not to
assign Type 1 RDs to MAC-VRFs should bear the consequences in mind, including
non-applicability of the solution suggested in Section 3.1.2 of the EVPN
Inter-Domain Option B
draft<https://datatracker.ietf.org/doc/html/draft-rabadan-bess-evpn-inter-domain-opt-b#section-3.1.2>.
However, neither 7432bis nor any other RFC or standard I am aware of says that
the same IP address PE address of the PE MUST (or, at least, SHOULD) be used as
the Administrator field of Type 1 RDs in per-ES A-D routes and Type 1 RDs
assigned to MAC-VRFs. And this is obviously a precondition for using the
solution suggested in Section 3.1.2.
IMHO and FWIW adding a corresponding RECOMMENDATION to the 7432bis draft would
be very much in place.
I also have some doubts regarding solution that is documented in Section 3.1.3
of the EVPN Inter-Domain Option B draft because:
* Only implementations that do not use OPTIONAL per EVI EVPN A-D routes can
benefit from this solution. In all other cases the per EVI Mass Withdrawal
solution (documented in Section 3.1 of the draft) would work exactly as well
* Such implementations could not benefit from aliasing and/or backup path
EVPN mechanisms (which inherently rely on per EVI EVPN A-D routes) , thus
severely compromising any benefits of the Mass Withdrawal mechanisms.
Hopefully these notes will be useful.
Regards,
Sasha
Regards,
Sasha
From: BESS <bess-boun...@ietf.org> On Behalf Of Jorge Rabadan (Nokia)
Sent: Friday, May 12, 2023 7:23 PM
To: wang.yub...@zte.com.cn;
draft-rabadan-bess-evpn-inter-domain-op...@ietf.org; rfc7432...@ietf.org
Cc: bess@ietf.org
Subject: [EXTERNAL] Re: [bess] Discussion on rfc7432bis and
draft-rabadan-bess-evpn-inter-domain-opt-b
Hi Yubao,
Thanks for reviewing the document.
I don’t see any conflicting information:
- On one hand the use of type 1 RD for MAC-VRF is RECOMMENDED in rfc7432bis,
which means that normally people will have a type 1 RD in MAC-VRFs. If you
don’t follow that strong recommendation for the MAC-VRF RD, you can’t use the
documented solutions in 3.1.2 or 3.1.3
- On the other hand draft-rabadan-bess-evpn-inter-domain-opt-b is documenting
some existing solutions, but not specifying or imposing any in particular..
So I don’t think there is conflicting information. But if you still think we
should clarify that in draft-rabadan-bess-evpn-inter-domain-opt-b we’ll be
happy to do it.
Thanks.
Jorge
From: wang.yub...@zte.com.cn<mailto:wang.yub...@zte.com.cn>
<wang.yub...@zte.com.cn<mailto:wang.yub...@zte.com.cn>>
Date: Friday, May 12, 2023 at 4:54 AM
To:
draft-rabadan-bess-evpn-inter-domain-op...@ietf.org<mailto:draft-rabadan-bess-evpn-inter-domain-op...@ietf.org>
<draft-rabadan-bess-evpn-inter-domain-op...@ietf.org<mailto:draft-rabadan-bess-evpn-inter-domain-op...@ietf.org>>,
Jorge Rabadan (Nokia)
<jorge.raba...@nokia.com<mailto:jorge.raba...@nokia.com>>,
rfc7432...@ietf.org<mailto:rfc7432...@ietf.org>
<rfc7432...@ietf.org<mailto:rfc7432...@ietf.org>>
Cc: bess@ietf.org<mailto:bess@ietf.org> <bess@ietf.org<mailto:bess@ietf.org>>
Subject: Discussion on rfc7432bis and draft-rabadan-bess-evpn-inter-domain-opt-b
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Hi Authors,
It seems that draft-rabadan-bess-evpn-inter-domain-opt-b has conflicting
discription with rfc7432 about the RD-type of AD per ES routes:
Section 3.1.3 of draft-rabadan-bess-evpn-inter-domain-opt-b-00: "If that is
the case, now the A-D per ES routes can use the route distinguisher assigned to
the EVPN Instance (or VRF), which is the same one used by the routes type 2 or
5 for the EVI."
Section 8.2.1 of rfc7432bis: "The Route Distinguisher MUST be a Type 1 RD
[RFC4364]. The value field comprises an IP address of the PE (typically, the
loopback address) followed by a number unique to the PE."
The RD of EVI is not always a Type 1 RD but rfc7432 says that the RD of AD per
ES route MUST be a Type1 RD. If it is not necessary to prevent other RD-types
from being used in AD per ES routes, is it better for rfc7432bis to change the
"MUST" to "MAY" ? I think such change is also compatible.
Thanks,
Yubao
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