Hi Stig,

Thanks for reviewing the draft and valuable feedback. I have addressed comments 
and posted a new version. Please see the response below.

Thanks,
Kesavan

From: Stig Venaas via Datatracker <[email protected]>
Date: Monday, September 29, 2025 at 3:40 PM
To: [email protected] <[email protected]>
Cc: [email protected] <[email protected]>, 
[email protected] 
<[email protected]>
Subject: draft-ietf-bess-evpn-mvpn-seamless-interop-09 early Rtgdir review
Document: draft-ietf-bess-evpn-mvpn-seamless-interop
Title: Seamless Multicast Interoperability between EVPN and MVPN PEs
Reviewer: Stig Venaas
Review result: Has Issues

I found the document well written and no serious issues.
There are however a few minor issues that I think should be resolved before it
is submitted to the IESG.

I see revision 06 was reviewed previously, please check that all those comments
are addressed.
review-ietf-bess-evpn-mvpn-seamless-interop-06-rtgdir-early-boucadair-2023-11-29-00

There are a few sentences that are hard to parse.

In section 5.2:
   sending these messages over MPLS/IP core.  A tenant virtual/physical
   router (e.g., CE) attached to an EVPN PE becomes a multicast routing
   the adjacency of that PE.  Furthermore, the PE uses MVPN BGP protocol

I don't understand the sentence ending with "the adjacency of that PE". Should
simply "the" be removed?
>> Removed

In section 5.3:
   attached behind EVPN PEs.  All VPN-IP routes SHOULD be summarized
   while adverting to MVPN PEs.

Replace "adverting" with "advertising"?
>> it is a typo. Addressed it.   ( Replaced with “advertising”)

In 6.1:
   In case of a TS, receiver sits behind an All-Active Multihoming ES
   and a TS source sits behind an inter-subnet tunnel (with respect to
   the multihomed PE), it is possible that more than one multihomed PEs
   sends MVPN join toward remote PE based on incoming join on their

Replace "more than one" with "more than one of the"?
>> Here, “more than one” is accurate one. It implies that it is possible for 
>> multiple PE to send MVPN join towards remote PE.

In 6.4:
   Here, IGMP/MLD states are terminated at IRB interfaces, and local
   interest are expressed in the context of IP-VRF to remote PEs.

s/are/is?

>> Corrected [ changed as “local interests” ]

In 7.2:
   Rcvr2 in Figure 1 is connected to PE1 in MAC-VRF2 and hence PE1 will
   record its membership in MAC-VRF2.  Since MAC-VRF2 is enabled with
   IRB, gets added as another OIF to the routing entry formed for (C-S,
   C-G).

What is it that gets added as another OIF?
>>  Replaced the  word “another OIF” as “an OIF”.

In 7.2:
   another OIF 'MAC-VRF2' to its existing routing entry.  But there is
   no change in control plane states since it is already sent MVPN route
   and no further signaling is required.  Traffic received by the tenant

Replace "it is already" with "it has already"?

>> Addressed the comment

In 8.1:
   It must be emphasized that this solution poses no restriction on the
   setup of the tenant BDs and that neither the source PE, nor the
   receiver PEs do not need to know/learn about the BD configuration on
   other PEs in the tenant IP-VRF ( Since EVPN PE is modeled as MVPN PE,
   source and receivers are announced to remote PE in the context of
   tenant IP-VRF(MVPN) as opposed to BD context).  The Reverse Path

This is hard to read with the double negative. Can "do not" be removed?
>> Sure, Modified the paragraph as follow. “It must be emphasized that this 
>> solution poses no restriction on the
  setup of the tenant BDs. The source PE and receiver PEs do not need to 
know/learn about the BD configuration on
   other PEs in the tenant IP-VRF”

In 8.1:
   EVPN PE MUST have Route Target Extended Community to import/export
   MVPN routes.  In a data center environment, it is desirable to have
   this RT is configured using an auto-generated method rather than a
   static configuration.

Replace "RT is" with "RT"?
>> Addressed it.

In 8.1:
   be appended as an export route-target extended community.  The PE
   which has advertised the unicast route with VRI, will import the
   incoming MCAST-VPN NLRI in the IP-VRF with the same import route-
   target extended-community and other PEs SHOULD ignore it.  Following

Why is this a SHOULD and not a MUST? What are the conditions where it makes
sense not to ignore it?

>> if someone configures import RT due to whatever reason which is beyond the 
>> scope of current document, route will be imported. Hence “SHOULD” is used 
>> here. If required, we can change this.

In 8.1:
   If the multicast source is unknown (overlay ASM mode), the MCAST-VPN
   route type 6 (C-*,C-G) join SHOULD be targeted towards the designated
   overlay Rendezvous Point (RP) by appending the received RP VRI as an
   export route-target extended community.  Every PE which detects a a

Also here, why is it a SHOULD and not a MUST. When does it make sense not to do
it?
>> changed “should be” as “is targeted”.  (This is an existing MVPN procedures )

In 8.2.2:
   When the encapsulation mode is configured as the VXLAN, the

Should it say "as VXLAN"?
>>  Changed as suggested

In 8.2.2:
   A gateway is needed for inter-operation between the EVPN MVPN-capable
   PEs and non-EVPN MVPN PEs.  The gateway should re-originate the
   control plane signaling with the relevant tunnel encapsulation on
   either side.  In the data plane, the gateway terminates the tunnels

Upper case SHOULD?
>>  Changed as suggested

Heading 12: TS RP options

What is TS?

>> “Tenant systems”. This is captured in the terminology section.

Section 13 IANA Considerations:

Maybe point out that references need to be updated when published?

>> It is taken care

Section 14 Security Considerations

Are there no new considerations due to how the existing technologies are
combined?
>> This draft leverages procedure defined in RFC 6513 and RFC 6514. Hence all 
>> security consideration for these RFC applies here.  I have added an 
>> operational consideration section in the new version, which discusses what 
>> needs to be considered for the seamless interop.

In A.3:
   Recent ASIC supports single lookup forwarding for bridging and
   routing (L2+L3).  The procedure mentioned here leverages this ASIC
   capability.

"Recent" may not age well. This document may be read years after publication.
It might also become multiple ASICs. I also find it a bit odd to mention ASIC
support. Maybe it makes more sense with ASIC support, but couldn't it be done
anyway?

That's all my issues.

>> Removed the ASIC reference and changed the sentences “The procedure 
>> mentioned here leverages single forwarding lookup for bridging and routing 
>> (L2+L3) capability”


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