Last Call Review of draft-ietf-bess-evpn-inter-subnet-forwarding-09
review-ietf-bess-evpn-inter-subnet-forwarding-09-opsdir-lc-jaeggli-2020-07-06-00

greetings,

I have reviewed draft-ietf-bess-evpn-inter-subnet-forwarding on behalf of the
ops directorate.

as a datacenter operator something of a conflict appears for me in this work in
that  I struggle with the state explosion that IRBs each host / subnet
represent on the PE switches. As the document says:

   In other words, each PE participating in
   asymmetric IRB MUST maintain ARP entries for remote hosts (hosts
   connected to other PEs) as well as maintain MAC-VRFs/BTs and IRB
   interfaces for ALL subnets in an IP VRF including subnets that may
   not be locally attached.

We designed ourselves into  a corner where we need this document.

it would be helpful if section 4 would be more explicit for non-implementors on
when symetric or asymetric modules would be chosen, as it stands the variation
basically reads like the enumeration of the features of various implementations.

I think this document is ready to proceed and it clearly addresses needs in
these implementations.

joel