[bess] [BESS] Conflicting rules among the Yang models on the association between IRB/AC interface and IP-VRF/MAC-VRF instance.

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Hi all,






I find some conflicting rules about interface-to-VRF binding between draft-ietf-rtgwg-ni-model-12 and draft-ietf-bess-l2vpn-yang-09.txt.


It is as below:






RULE1: [NI-model] Section 3.2 says that:

The bind-network-instance-name leaf provides the association between an

   interface and its associated NI (e.g., VRF or VSI). 


RULE2: [draft-ietf-bess-evpn-yang-06] Section 3.3 says that:


     augment 

     /ni:network-instances/ni:network-instance/ni:ni-type/l2vpn:l2vpn:

       +--rw evpn-instance?   evpn-instance-ref


and [draft-ietf-bess-l2vpn-yang-09.txt] Section 3.6.3 says that:

   Each entry in the endpoint list, may hold AC, PW or redundancy-grp

   references.  The core aspect of endpoint container is its flexible

   personality based on what user decides to include in it.  It is

   future-proofed with possible extensions that can be included in the

   endpoint container such as Integrated Route Bridging (IRB), PW

   Headend, Virtual Switch Instance, etc.






According to the RULE1, The bind-network-instance-name leaf provides the association between an interface and its associated MAC-VRF or IP-VRF.


According to the RULE2, IRB/AC interface is associated to it's EVPN MAC-VRF via the "end-point" entry.






So I have the follow two questions:


Question 1: How should I bind an AC to it's EVPN MAC-VRF according to these drafts? 


Question 2: How should I bind an IRB interface to it's EVPN MAC-VRF and EVPN IP-VRF according to these drafts?






For Question 1, my understanding is as below:


I should follow the RULE2 to bind an AC to it's associated EVPN MAC-VRF.


The RULE1 doesn't work for L2VPN ACs,


because if the RULE1 is applied to the association between AC and its associated MAC-VRF, 


It should be applied to the association between IRB interface and its associated MAC-VRF too.


But obviously the RULE1 should be applied to the association between IRB interface and its associated IP-VRF.






Consequently, for Question 2, my understanding is as below:


I should follow the RULE1 to bind an IRB to it's associated EVPN IP-VRF.


I should follow the RULE2 to bind an IRB to it's associated EVPN MAC-VRF.






Is my understanding correct?






Best Regards


Bob