[bess] Yet another minor inconsistency in draft-ietf-bess-rfc7432bis

[Alexander Vainshtein <[e-mail]>]

Hi,
I would like to present what looks to me as yet another minor inconsistency in the rfc7432bis draft.<https://datatracker.ietf.org/doc/html/draft-ietf-bess-rfc7432bis-10>

Section 9.2.1 lists four possible methods for allocating the label that is carried in the Label1 field of the NLRI of MAC/IP Advertisement (EVPN Type 2) routes as shown below:


  *   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.¶<https://datatracker.ietf.org/doc/html/draft-ietf-bess-rfc7432bis-10#section-9.2.1-9.1>
  *   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.¶<https://datatracker.ietf.org/doc/html/draft-ietf-bess-rfc7432bis-10#section-9.2.1-9.2>
  *   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.¶<https://datatracker.ietf.org/doc/html/draft-ietf-bess-rfc7432bis-10#section-9.2.1-9.3>
  *   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.¶<https://datatracker.ietf.org/doc/html/draft-ietf-bess-rfc7432bis-10#section-9.2.1-9.4>

However, an EVI that implements VLAN-aware bundle service interface as defined in Section 6.3 of the draft, the same MAC address may be locally learned in different BDs (identified by their Ethernet Tag IDs) in the same MAC-VRF.
To me this suggests that there is (at least in theory) there is the fifth option, in which a unique EVPN label would be allocated per <MAC-VRF, locally learned MAC address, Ethernet Tag ID> combination.

Hopefully this note will be useful.





Regards,
Sasha

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