[bess] Chair review of draft-ietf-bess-evpn-bum-procedure-updates

[<[e-mail]>]

Hi,

 

Before moving forward to IESG, here is my review of the document:

 

Section 2:

"Note that these are to be applied
   to EVPN only, even though sometimes they may sound to be updates to
   [ <https://tools.ietf.org/html/rfc7117> RFC7117] or [
<https://tools.ietf.org/html/rfc7524> RFC7524]. >

The second part of the sentence is not really appropriate for a standard
document. The text should always be crystal clear that it applies to EVPN
only, reuse the procedures from other RFCs with the associated
modifications. But you must never talk about updating VPLS RFCs, if you
don't.

 

Section 3:

Not all the route types are coming from RFC7432, could you provide a
reference for route-types that are not defined in RFC7432 ?

 

Section 3.1:

As you say in the text, the extended community is not an attribute here.
Wouldn't it be better to rename it as Region ID, telling then in the text
that it is encoded similarly to an extended community using type/subtype/.

In case you agree, update of 6.2 is necessary.

 

 

Section 4:

s/and an receiving NVE/and a receiving NVE

s/In a nut shell/In a nutshell

s/S-SPMSI/S-PMSI

 

s/an egress NVE may omit the Leaf/an egress NVE MAY omit the Leaf

s/if it already advertises/if it has already advertised

s/and the source NVE will use that/and the source NVE MUST use that

 

Section 5.1

In the proposal text changes for 7.2.2.4 in RFC7117, please use normative
language s/must/MUST

 

Section 5.2:

I don't understand this sentence (ps: I'm not telling the sentence is wrong)
:

"Note
   that in case of Ingress Replication, when an ASBR re-advertises IBGP
   I-PMSI A-D routes, it MUST advertise the same label for all those for
   the same Ethernet Tag ID and the same EVI. "

Could you please explain me ? Do you mean that ASBR allocate the same label
for different routes with same ETAG/EVI ?

 

Consider the following setup

 

PE1 -(CORE)-- ASBR1 ---- ASBR2 ---(CORE)  ---PE2

                      --ASBR3 --- ASBR4 ---         ------- PE3

 

PE1 being the source of BUM.

 

PE2 and PE3 send IMET route for EVI1/ETAG1 respectively with label 20 and 30
(IR assumed).

ASBR2 and ASBR4 sends the route as Inter-AS A-D routes setting themselves as
NH and using PTA type set to IR. Does it set a different label value for
each Inter-AS A-D route ?

I understand that the behavior described above (from your draft) applies to
ASBR1 and ASBR3 which will readvertise the same label for both routes but
why not doing the label aggregation at ASBR2/4 ?

The text talks about I-PMSI A-D routes, but do you confirm that you talk
about Inter-AS I-PMSI A-D routes ?

 

In addition, you should use normative language in :

"When an ingress PE builds
   its flooding list, multiple routes may have the same (nexthop, label)
   tuple and they will only be added as a single branch in the flooding
   list. >