Hi Joege,

Thanks for your detail explanations.

Yes, there are two Option-B solutions as follows.

1. No MAC VRF is created on DC GW, no sub interfaces associated with each VRF 
are created between DC GW and WAN PE. Only VN ID and MPLS VPN Label switching 
is performed on DC GW for unicast traffic forwarding. This solution is 
equivalent option-B of RFC 4364.

2. MAC VRF is created on DC GW,  MPLS VPN Label is allocated per VRF,no sub 
interfaces associated with each VRF are created between DC GW and WAN PE.



The above second solution is your solution. It has no problem. Several months 
ago, Robert and I had already proposed this solution, pls read our draft 
https://tools.ietf.org/html/draft-hao-l3vpn-inter-nvo3-vpn-01(section 7), and 
we think the above two solutions can be hybrid deployed, which means from WAN 
to DC direction using the second solution, from DC to WAN direction using the 
first solution.



Thanks

weiguo

________________________________

From: Rabadan, Jorge (Jorge) [[email protected]]
Sent: Saturday, November 15, 2014 12:27
To: Haoweiguo; [email protected]
Subject: Re: 答复: [bess] 答复: Comments on draft 
draft-rabadan-bess-dci-evpn-overlay-00

Hi Weiguo,

My apologies but I don’t get what you think I missed :-)
draft-rabadan-bess-dci-evpn-overlay describes a gateway solution that does not 
match an RFC4364-“equivalent" model (*)
draft-ietf-bess-evpn-overlay-00 describes an Inter-AS solution that matches an 
RFC4364-“equivalent” model-B.

(*) Model A means MAC-VRF to MAC-VRF connected through sub-interfaces, i.e. 
attachment circuits. This is only the case in section 2.2 of the decoupled 
model. The rest of the sub-models do not match this description. In particular, 
one of the models: section 3.4 EVPN-MPLS interconnect for EVPN-Overlay 
networks, uses EVPN at both sides:

  *   This is in no way model A, since a) MP-BGP is used at both sides, to the 
DC RR and to the WAN RR and b) no sub-interfaces are used to get connected to 
the WAN PEs.
  *   A MAC-VRF is instantiated in the GW due to the requirements explained in 
the document.
  *   We are not comparing the scalability of this solution vs the Inter-AS 
solution explained in draft-ietf-bess-evpn-overlay-00. We are just providing a 
needed solution given the stated requirements.
  *   It is understood that this requires MAC lookup hence storing MACs in the 
FIB, but has many other advantages over an inter-AS model B solution. For 
instance:
     *   It provides protection/isolation to the DC (control over the 
advertised MACs, proxy-ARP/ND, unknown-mac-route)
     *   Allows local ACs
     *   Label aggregation: in model B the GW advertises to the WAN a label per 
NVE per MAC-VRF and the other way around (a label per PE per MAC-VRF to the 
DC). In our model a single label is advertised per MAC-VRF to the WAN and the 
other way around. So from the label perspective, it helps scaling the DC and 
the WAN network more than model B.
     *   Also provides WAN and DC independency in terms of inclusive multicast 
trees, MAC mobility and other procedures.

Some slides about it:
http://www.ietf.org/proceedings/89/slides/slides-89-l2vpn-2.pdf

Thanks.
Jorge

From: Haoweiguo <[email protected]<mailto:[email protected]>>
Date: Friday, November 14, 2014 at 3:14 PM
To: Jorge Rabadan 
<[email protected]<mailto:[email protected]>>, 
"[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>>
Subject: 答复: [bess] 答复: Comments on draft draft-rabadan-bess-dci-evpn-overlay-00


Hi Joege,

Sorry, may be you missed it. Your discription is Option-A solution between NVO3 
GW and EVPN PE, not Option-B solution. In option-B case, no MAC VRFs are 
required on GW, only VN ID and MPLS VPN Label switching is needed, it has 
bettter scalability than option-A.

Thanks

weiguo

________________________________
发件人: BESS [[email protected]<mailto:[email protected]>] 代表 Rabadan, 
Jorge (Jorge) 
[[email protected]<mailto:[email protected]>]
发送时间: 2014年11月15日 1:23
收件人: Haoweiguo; [email protected]<mailto:[email protected]>
主题: Re: [bess] 答复: Comments on draft draft-rabadan-bess-dci-evpn-overlay-00

Weiguo,

In-line [JORGE2].
Thanks.

From: Haoweiguo <[email protected]<mailto:[email protected]>>
Date: Friday, November 14, 2014 at 1:08 AM
To: Jorge Rabadan 
<[email protected]<mailto:[email protected]>>, 
"[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>>
Subject: [bess] 答复: Comments on draft draft-rabadan-bess-dci-evpn-overlay-00


Hi Jorge,

Please see inline with [weiguo2].

Thanks

weiguo

________________________________
发件人: Rabadan, Jorge (Jorge) 
[[email protected]<mailto:[email protected]>]
发送时间: 2014年11月13日 16:42
收件人: Haoweiguo; [email protected]<mailto:[email protected]>
主题: Re: [bess] Comments on draft draft-rabadan-bess-dci-evpn-overlay-00

Hi Weiguo,

Please see in-line.

From: Haoweiguo <[email protected]<mailto:[email protected]>>
Date: Wednesday, November 12, 2014 at 11:09 PM
To: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>>
Subject: [bess] Comments on draft draft-rabadan-bess-dci-evpn-overlay-00


Hi Co-authors,

In today's BESS meeting, i have some comments, pls allow me to reiterate here.

1. EVPN supports mass MAC withdraw when local PE link failure occurs. If EVPN 
is used for NVO3 network interconnecting, if a local NVE occurs node failure, 
local DCI PE how to notify remote PEs to flush MAC table in mass mode, because 
in this case, there maybe many TS's MAC attached to the local NVE, mass MAC 
withdraw should be supported to provide MAC withdraw efficiecy.

[JORGE] If you are talking about the EVPN-MPLS interconnect model, if there is 
a failure in one of the ESIs at an NVE, the NVE will withdraw the A-D per ESI 
route and the DC GWs will do mass withdraw. That is perfectly supported. The 
NVE ESI A-D route updates/withdraw don’t have to be exported to the WAN PEs.

[weiguo2]: Sorry, it's my mistake, too many similar drafts. In the draft no 
this issue. in your draft data center network is NVO3+EVPN, control plane mac 
learning is used. There is another draft, NVO3 uses data plane MAC learning, no 
EVPN protocol is running within data center network, in this case NVE occurs 
link or node failure, no MASS mac withdraw mechanism.



2. For EVPN multi-homing, DF is elected per I-ESI, can you ensure BUM traffic 
load balancing among multiple PEs?

[JORGE] See the procedures in section 3.4.3.
[weiguo2]: Yes, It can realize per EVI loadbalancing.


3. If DC GW and WAN PE are separated device, Option-B solution should be 
supprted to ensure scalability, Option-A (In your draft, it is called vlan 
hand-off)has two much scalability limitations.

[JORGE] The decoupled model assumes separate admin entities in WAN and DC, 
hence you need a clear demarcation hand off for security and QoS, etc. Of 
course the decouple vs integrated model described in the draft have pros and 
cons, but both are required. Option B is described in 
http://tools.ietf.org/html/draft-sd-l2vpn-evpn-overlay-03

For unicast traffic, the DC GW should support VN ID and MPLS VPN Label 
switching. VN ID and MPLS VPN Label at WAN PE assign machanism also should be 
specified. For BUM traffic, the DC GW should stitch the multicast tree within 
data center and the multicast tree in WAN network.

The description is too simple in your draft, in our previous drafts, the 
option-B solution is described in detail,  your reading are welcomed.

http://datatracker.ietf.org/doc/draft-hao-l2vpn-inter-nvo3-evpn/

http://ietfreport.isoc.org/idref/draft-hao-l3vpn-inter-nvo3-vpn/





[JORGE] If you refer to section 3.4, all the procedures which are *different 
from EVPN* are described in the draft in my opinion. I don’t think EVPN 
procedures have to be explained here, but let us know if there is something 
specific that can be subject to different interpretations.

[weiguo2]: Option-B solution only applies for decouple model. I think the 
solution in your referrence is not clear, if you have spare time, pls read the 
above two drafts. VN ID and MPLS VPN Label assigning principle, how to stitch 
service layer including unicast and multicast are all described in detail. 
Thanks.

[JORGE2] To be clear, this draft does not talk about option B. That is 
explained in the evpn-overlay draft. This draft defines a gateway function, 
where a MAC-VRF is instantiated in the GW, i.e. a MAC lookup is required. As 
such, stitching and translations VNI to VNI or VNI to MPLS label are all fully 
supported. The VNIs or MPLS labels are locally allocated and there are no 
dependencies because we always do a MAC lookup. Can you please let us know what 
exactly is not clear?
Another comment: the decouple vs integrated thing is terminology of this draft 
and it is not used anywhere else, and IMO it does not make sense when talking 
about option B.




In my today's Option-C presentation, transport layer stitching mechanism is 
described. Option-B solution should support service layer stitching, the 
mechansim also should be fully described.



[JORGE] As discussed, personally I think I understand your solution but at the 
moment I haven’t seen any use-case for such complex architecture. I have only 
seen use cases for model B or for the GW model described in the 
dci-evpn-overlay draft.
[weiguo2]: Currently NVO3 networks have not been widely deployed, so you 
haven't seen any usecases for option-C. But maybe in the future, it will be 
used, because it is a equivalent solution of vanilla option-C in RFC4364.



Thanks

weiguo
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