Hi, Jeffery: Thanks for your analysis. Let’s try again to converge based on our current mutual understandings.
First, the conclusion, the solution proposed in this document is necessary. Here is the reasoning: What you quoted at https://www.rfc-editor.org/rfc/rfc7432.html#section-9.2.1 is just the traditional layer 2 access EVPN services or one of our layer 3 accessible EVPN service(“LSI based EVPN services”), the protocol extensions proposed in draft-wang-bess-l3-accessible-evpn is mainly for “LSI Aware Bundle EVPN services”, which is not covered by the current RFC7432, or any other existing EVPN related services. For example: A PE may advertise the same single EVPN label for all MAC addresses in a given MAC-VRF. This label assignment is referred to as a per MAC-VRF label assignment. —-The above description corresponds to “Layer 2 VLAN Bundled EVPN Service” Alternatively, a PE may advertise a unique EVPN label per <MAC-VRF, Ethernet tag> combination. This label assignment is referred to as a per <MAC-VRF, Ethernet tag> label assignment. —-The above description corresponds to “Layer 2 VLAN Based EVPN Service” As a third option, a PE may advertise a unique EVPN label per <ESI, Ethernet tag> combination. This label assignment is referred to as a per <ESI, Ethernet tag> label assignment. —-The above description corresponds to “LSI Based EVPN Service”. As a fourth option, a PE may advertise a unique EVPN label per MAC address. This label assignment is referred to as a per MAC label assignment. —-The above description is just for some very specific situations, and is not in the scope of current “Layer 2 Access EVPN Service” or the corresponding newly proposed “Layer 3 accessible EVPN service” All of these label assignment methods have their trade-offs. The choice of a particular label assignment methodology is purely local to the PE that originates the route Aijun Wang China Telecom Aijun Wang China Telecom > On Mar 17, 2025, at 05:12, Jeffrey (Zhaohui) Zhang > <zzhang=40juniper....@dmarc.ietf.org> wrote: > Hi Aijun, > > Now that the -08 revision has been published, let me bring this discussion to > the WG. The email thread has some details that help clarify the intended use > case and why the proposed solution is not needed or not good. > > The draft does not clearly state it, but based on our discussions below, the > PE-CE connection is a PW that terminates into the EVPN PE. There are two > previous points that I want to re-emphasize here. I'll then explain why your > proposed solution is not needed in my view. > > - There are already deployed solutions of PWs terminating into VPN service > PEs, including EVPN, w/o any protocol extensions > - On the EVPN side, there is no difference between "a PW terminates into a > PW-PE, which then connects to EVPN PE via a physical L2 connection" and "a PW > terminates into the EVPN PE directly" > > Your solution requires the ingress EVPN PEs to put on the PW information that > is used on the egress side. That is just unnecessary and not appropriate. > > In the true L2 connection case, the MAC lookup on the egress PE leads to > local forwarding information, including the outgoing AC and perhaps VID > translation information. > In the PW terminating into EVPN PE case, the same lookup leads to local > forwarding information, including the PW information, which is *local* and > should not be advertised other EVPN PEs for them to put into the VXLAN header. > > If your intention is to avoid the MAC lookup on the egress PE (which the > draft does not talk about), it is an orthogonal issue (nothing to do with PW > terminating into EVPN PE) that is already solved. Per RFC7432: > > A PE may advertise the same single EVPN label for all MAC addresses > in a given MAC-VRF. This label assignment is referred to as a per > MAC-VRF label assignment. Alternatively, a PE may advertise a unique > EVPN label per <MAC-VRF, Ethernet tag> combination. This label > assignment is referred to as a per <MAC-VRF, Ethernet tag> label > assignment. As a third option, a PE may advertise a unique EVPN > label per <ESI, Ethernet tag> combination. This label assignment is > referred to as a per <ESI, Ethernet tag> label assignment. As a > fourth option, a PE may advertise a unique EVPN label per MAC > address. This label assignment is referred to as
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