Hi Anoop,





Please see my response inline with [XM].



原始邮件



发件人:AnoopGhanwani <an...@alumni.duke.edu>
收件人:肖敏10093570;
抄送人:draft-ietf-bfd-vx...@ietf.org <draft-ietf-bfd-vx...@ietf.org>;nvo3@ietf.org 
<nvo3@ietf.org>;rtg-bfd WG <rtg-...@ietf.org>;
日 期 :2019年10月10日 15:47
主 题 :Re: [nvo3] BFD over VXLAN: Trapping BFD Control packet at VTEP


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Hi Xiao Min,
In those cases, the term "VN" is used to talk about multiple IP interfaces in a 
VRF.  The different interfaces would have to be different VNIs.

[XM] To be clear, I interpret VNI as Virtual Network Identifier that should be 
present within VxLAN/Geneve header. Do you mean in the case multiple Tenant 
Systems connect to multiple NVEs through IP routing network, different NVEs 
must encapsulate different Virtual Network Identifiers?


In the mixed case (with MPLS and L2 hitting the NVE at different VAPs), I'm not 
sure how it would work in the same VNI.  If you think it's important, I think 
it may be worth writing it up.  If there's enough merit in the use case, we can 
figure out how to run multiple BFD sessions on the same VNI.

[XM] As to the mixed case, I don't know whether there's enough merit, I just 
raise it for discussion because it seems not being prohibited from the NVO3 
architecture point of view.




Anoop







Best Regards,


Xiao Min






On Wed, Oct 9, 2019 at 11:06 PM <xiao.m...@zte.com.cn> wrote:


Hi Anoop,






Normally, it is. While Tenant Systems connect to NVE through IP routing network 
or MPLS forwarding network, it is not.






Best Regards,


Xiao Min



原始邮件


发件人:AnoopGhanwani <an...@alumni.duke.edu>
收件人:肖敏10093570;
抄送人:draft-ietf-bfd-vx...@ietf.org <draft-ietf-bfd-vx...@ietf.org>;nvo3@ietf.org 
<nvo3@ietf.org>;rtg-bfd WG <rtg-...@ietf.org>;
日 期 :2019年10月10日 05:33
主 题 :Re: [nvo3] BFD over VXLAN: Trapping BFD Control packet at VTEP



Hi Xiao Min,
Normally, I think of a VNI as a broadcast domain.  The only way I can make 
sense of the picture below is to have a separate VNI for each MPLS interface on 
the NVE.

Anoop




On Tue, Oct 8, 2019 at 11:09 PM <xiao...m...@zte.com.cn> wrote:


Hi Anoop,







In this use case there is no forwarding happens between the MPLS and non-MPLS 
parts, would this use case be prohibited?


If the answer is yes, then I agree that all Tenant Systems attached to a common 
NVE MUST share a VAP so long as they connect to the same VN, although in 
RFC8014 it uses "can" but not "MUST". As a result, we should not allow multiple 
BFD sessions for the same VNI between two NVEs.


If the answer is no, then we should allow multiple BFD sessions for the same 
VNI between two NVEs. I personally lean to this answer.






Best Regards,


Xiao Min



原始邮件


发件人:AnoopGhanwani <an...@alumni.duke.edu>
收件人:肖敏10093570;
抄送人:Greg Mirsky <gregimir...@gmail.com>;did...@gmail.com 
<did...@gmail.com>;draft-ietf-bfd-vx...@ietf.org 
<draft-ietf-bfd-vx...@ietf.org>;nvo3@ietf.org 
<nvo3@ietf.org>;santosh...pallaga...@gmail.com 
<santosh.pallaga...@gmail.com>;rtg-bfd WG <rtg-...@ietf.org>;Joel M. Halpern 
<j...@joelhalpern.com>;tsrid...@vmware.com <tsrid...@vmware.com>;
日 期 :2019年10月09日 06:28
主 题 :Re: [nvo3] BFD over VXLAN: Trapping BFD Control packet at VTEP


Hi Xiao Min,
The picture doesn't have enough information to explain why they are in the same 
VNI, and exactly how forwarding happens between the MPLS and non-MPLS parts.

Anoop




On Tue, Oct 8, 2019 at 12:31 AM <xiao.m...@zte.com.cn> wrote:


Hi Anoop,







I don't know such a draft that describes MPLS over Geneve, but I believe the 
following figure derived from figure 1 of RFC8014 would help, in the following 
figure Tenant System1, Tenant System2, Tenant System3 and Tenant System4 are 
assumed belonging to the same VNI, so two BFD sessions for the same VNI need to 
be run between NVE1 and NVE2.

 +--------+
 +----| Tenant |
 ( ' ) | System1|
 ................ ( MPLS ) +--------+
 . . +--+-+ ( _ )
 . .--|NVE1|---+
 . . | |
 . . +--+-+
 . . |
 . L3 Overlay . ( ' )
 . Network . (Ethernet)
 . . ( _ )
 . . |
 ................ +--------+
 | | Tenant |
 +----+ | System2|
 |NVE2| +--------+
 | |--------+
 +----+ |
 | |
 ( ' ) ( ' )
 ( MPLS ) (Ethernet)
 ( _ ) ( _ )
 | |
 +--------+ +--------+
 | Tenant | | Tenant |
 | System3| | System4|
 +--------+ +--------+




Best Regards,


Xiao Min



原始邮件


发件人:AnoopGhanwani <an...@alumni...duke.edu>
收件人:肖敏10093570;
抄送人:Greg Mirsky <gregimir...@gmail.com>;did...@gmail...com 
<did...@gmail.com>;draft-ietf-bfd-vx...@ietf.org 
<draft-ietf-bfd-vx...@ietf.org>;nvo3@ietf.org 
<nvo3@ietf.org>;santosh.pallaga...@gmail.com 
<santosh.pallaga...@gmail.com>;rtg-bfd WG <rtg-...@ietf.org>;Joel M. Halpern 
<j...@joelhalpern.com>;tsrid...@vmware.com <tsrid...@vmware.com>;
日 期 :2019年10月08日 12:15
主 题 :Re: [nvo3] BFD over VXLAN: Trapping BFD Control packet at VTEP



Hi Xiao Min,
Is there a draft that describes MPLS over Geneve?  It sounds like the NVE is an 
MPLS router in this case and if you're using the same VNI as you switch MPLS, 
then it's a one-armed router.  That doesn't change how BFD needs to be run 
between NVEs.

Anoop




On Mon, Oct 7, 2019 at 7:28 PM <xiao.m...@zte.com.cn> wrote:


Hi Anoop,






Sorry for the late response, I just come back from vacation.


The use case is that the network between the VM and the NVE is an MPLS network, 
within which the packet is forwarded basing on MPLS label, but not Ethernet MAC 
address and/or 802.1Q VLAN. When two such kind of MPLS networks need to 
communicate with each other, through a Geneve tunnel, the encap I illustrated 
would be used.






Best Regards,


Xiao Min



原始邮件


发件人:AnoopGhanwani <an...@alumni.duke.edu>
收件人:肖敏10093570;
抄送人:Greg Mirsky <gregimir...@gmail.com>;did...@gmail.com 
<did...@gmail.com>;draft-ietf-bfd-vx...@ietf.org 
<draft-ietf-bfd-vx...@ietf.org>;nvo3@ietf.org 
<nvo3@ietf.org>;santosh.pallaga...@gmail.com 
<santosh.pallaga...@gmail.com>;rtg-bfd WG <rtg-...@ietf.org>;Joel M. Halpern 
<j...@joelhalpern...com>;tsrid...@vmware.com <tsrid...@vmware.com>;
日 期 :2019年09月28日 05:36
主 题 :Re: [nvo3] BFD over VXLAN: Trapping BFD Control packet at VTEP



Hi Xiao Min,
Thanks for the details about the encap but the use case is not clear.  It might 
help if you explain why its necessary to map a physical Ethernet port and/or 
802.1Q VLAN to the same VNI as an MPLS packet without an L2 header.

Thanks,
Anoop




On Thu, Sep 26, 2019 at 7:50 PM <xiao.m...@zte.com.cn> wrote:


Hi Anoop,






Due to the fact that a variety of Tunnels could be used under the NVO3 
architecture, as an example, below figure illustrates the format of MPLS packet 
over Geneve Tunnel.




 0 1 2 3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | |
 ~ Outer Ethernet Header ~
 | |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | |
 ~ Outer IPvX Header ~
 | |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | |
 ~ Outer UDP Header ~
 | |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 | |
 ~ Geneve Header ~
 | |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+<-+
 | | |
 ~ MPLS Label Stack ~ M
 | | P
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ L
 | | S
 | |
 ~ Payload ~ P
 | | K
 | | T
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+<-+
 | FCS |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+





Note that in NVO3 working group Greg and I have submitted an individual draft 
draft-xiao-nvo3-bfd-geneve, which is used to address BFD over Geneve.

The intention is to make the two drafts draft-ietf-bfd-vxlan and 
draft-xiao-nvo3-bfd-geneve aligned, that is to say, we try to define the 
identical mechanism for the common part of BFD over VxLAN Tunnel and BFD over 
Geneve Tunnel. For the common part, draft-xiao-nvo3-bfd-geneve would reference 
to draft-ietf-bfd-vxlan, and for the other part specific to Geneve, we'll 
define the specific mechanism in draft-xiao-nvo3-bfd-geneve.




Hope that clarifies.




Best Regards,

Xiao Min



原始邮件


发件人:AnoopGhanwani <an...@alumni.duke.edu>
收件人:肖敏10093570;
抄送人:Greg Mirsky <gregimir...@gmail.com>;did...@gmail.com 
<did...@gmail.com>;draft-ietf-bfd-vx...@ietf.org 
<draft-ietf-bfd-vx...@ietf.org>;nvo3@ietf.org 
<nvo3@ietf.org>;santosh.pallaga...@gmail.com 
<santosh.pallaga...@gmail.com>;rtg-bfd WG <rtg-...@ietf.org>;Joel M. Halpern 
<j...@joelhalpern.com>;tsrid...@vmware.com 
<tsrid...@vmware...com>;bfd-cha...@ietf.org <bfd-cha...@ietf.org>;
日 期 :2019年09月26日 23:16
主 题 :Re: [nvo3] BFD over VXLAN: Trapping BFD Control packet at VTEP



Hi Xiao Min,
I think we would need more detail around the use case below.  What does the 
MPLS packet over Tunnel look like?

Thanks,
Anoop




On Wed, Sep 25, 2019 at 11:37 PM <xiao.m...@zte.com.cn> wrote:


Hi Anoop,






Thanks for your comments.


Considering a scenario where TS1 has an MPLS access (i.e. MPLS-Packet over 
Tunnel between NVEs) to VNI1, TS3 has an Ethernet access (i.e. MAC-Frame over 
Tunnel between NVEs) to VNI1, then how can TS1 and TS3 share one VAP?






Best Regards,


Xiao Min



原始邮件


发件人:AnoopGhanwani <an...@alumni.duke.edu>
收件人:肖敏10093570;
抄送人:Greg Mirsky <gregimir...@gmail.com>;did...@gmail.com 
<did...@gmail.com>;draft-ietf-bfd-vx...@ietf.org 
<draft-ietf-bfd-vx...@ietf.org>;nvo3@ietf.org 
<nvo3@ietf.org>;santosh.pallaga...@gmail.com 
<santosh.pallaga...@gmail.com>;rtg-bfd WG <rtg-...@ietf.org>;Joel M. Halpern 
<j...@joelhalpern.com>;tsrid...@vmware.com 
<tsrid...@vmware.com>;bfd-cha...@ietf.org <bfd-cha...@ietf.org>;
日 期 :2019年09月26日 08:36
主 题 :Re: [nvo3] BFD over VXLAN: Trapping BFD Control packet at VTEP

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>>>

Some people may argue that all Tenant Systems connecting to the same Virtual 
Network MUST share one VAP, if that's true, then VAP1 and VAP3 should merge 
into one VAP and my explanation doesn't work. Copying to NVO3 WG to involve 
more experts, hope for your clarifications and comments.  


>>>

I would be one of those that would argue that they MUST share on VAP if they 
connect to the same Virtual Network.  IMO, the NVO3 arch doc should have been 
clearer about this.

Thanks,
Anoop



On Tue, Sep 24, 2019 at 7:40 PM <xiao.m...@zte.com.cn> wrote:


Hi Santosh,






With regard to the question whether we should allow multiple BFD sessions for 
the same VNI or not, IMHO we should allow it, more explanation as follows...


Below is a figure derived from figure 2 of RFC8014 (An Architecture for 
Data-Center Network Virtualization over Layer 3 (NVO3)).




 | Data Center Network (IP) |
 | |
 +-----------------------------------------+
 | |
 | Tunnel Overlay |
 +------------+---------+ +---------+------------+
 | +----------+-------+ | | +-------+----------+ |
 | | Overlay Module | | | | Overlay Module | |
 | +---------+--------+ | | +---------+--------+ |
 | | | | | |
 NVE1 | | | | | | NVE2
 | +--------+-------+ | | +--------+-------+ |
 | |VNI1 VNI2 VNI1 | | | | VNI1 VNI2 VNI1 | |
 | +-+-----+----+---+ | | +-+-----+-----+--+ |
 |VAP1| VAP2| | VAP3 | |VAP1| VAP2| | VAP3|
 +----+-----+----+------+ +----+-----+-----+-----+
 | | | | | |
 | | | | | |
 | | | | | |
 -------+-----+----+-------------------+-----+-----+-------
 | | | Tenant | | |
 TSI1 | TSI2| | TSI3 TSI1| TSI2| |TSI3
 +---+ +---+ +---+ +---+ +---+ +---+
 |TS1| |TS2| |TS3| |TS4| |TS5| |TS6|
 +---+ +---+ +---+ +---+ +---+ +---+
To my understanding, the BFD sessions between NVE1 and NVE2 are actually 
initiated and terminated at VAP of NVE.


If the network operator want to set up one BFD session between VAP1 of NVE1 and 
VAP1of NVE2, at the same time another BFD session between VAP3 of NVE1 and VAP3 
of NVE2, although the two BFD sessions are for the same VNI1, I believe it's 
reasonable, so that's why I think we should allow it.






Of course, in RFC8014 it also says:

"Note that two different Tenant Systems (and TSIs) attached to a common NVE can 
share a VAP (e.g., TS1 and TS2 in Figure 2) so long as they connect to the same 
Virtual Network."
Some people may argue that all Tenant Systems connecting to the same Virtual 
Network MUST share one VAP, if that's true, then VAP1 and VAP3 should merge 
into one VAP and my explanation doesn't work. Copying to NVO3 WG to involve 
more experts, hope for your clarifications and comments.






Best Regards,


Xiao Min





























































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