Subject: [bess] Comments about draft-ietf-bess-evpn-bfd-03

From: "Rabadan, Jorge (Nokia - US/Mountain View)" <[email-masked]>
Date: Wed, 10 Mar 2021 09:21:52 +0000

Dear authors,

(Most of) these comments were made during the last IETF as well. Thank you in advance for considering them.

  1.  About fault detection for unicast:

By default, it advertises this discriminator with

   BGP using the BFD Discriminator Attribute [ietf-bess-mvpn-fast-

   failover] with BFD Mode TBD4 in an EVPN MAC/IP Advertisement Route

   [RFC7432<https://datatracker.ietf.org/doc/html/rfc7432>] and extracts its peer's discriminator from such an

   attribute.

In typical EVPN deployments there are no MAC/IP advertisement routes advertised by a PE until the PE does not learn a MAC for a locally attached host. Based on the text above, the operator cannot establish BFD session against an EVPN PE that has not learn a local MAC yet.
Is that the intend? Or is the intend to advertise a local management MAC for the purpose of distributing the BFD discriminator required for unicast fault detection? Or is it the MAC allocated in section 8.2?
Please add text is missing to clarify this.

  1.  Unicast mpls encapsulation

- The destination IP port MUST be 3784 [RFC5881<https://datatracker.ietf.org/doc/html/rfc5881>].

s/IP port/UDP port/

  1.  The draft does not support BDF for IP multicast traffic in EVPN networks

  *   Is this intended?
  *   Are you planning to address this gap? If so, text is needed and the discriminator added to S-PMSI A-D routes.

Thanks.
Jorge