Re: [bess] WG Last Call on draft-ietf-bess-evpn-etree

[<[e-mail]>]

Hi everyone,

This WG Last Call is now closed and the document will move to the next 
steps toward publication.

The modification mentioned below will be incorporated in next release.

Best,

-Thomas



2016-03-15, Ali Sajassi (sajassi):
>
> Jeffrey,
>
>
>
> On 2/1/16, 2:41 PM, "Jeffrey (Zhaohui) Zhang" <[e-mail]> wrote:
>
>> Ali,
>>
>> One more question about PBB-EVPN.
>>
>> For the regular EVPN, section 3.3.2 talks about a situation where the
>> only traffic is BUM. There is no need for mac learning in that situation.
>>
>> For PBB-EVPN, I assume this is also possible. With this, there is no need
>> to advertise per-ES B-mac addresses - a single pair of global root/leaf
>> B-mac addresses are enough.
>>
>> Perhaps this can be mentioned for parity/completeness. Of course, this is
>> not a big deal and either way it's fine - but I do want to ask to confirm
>> my understanding.
>
> We’ll do.
>
> Cheers,
> Ali
>
>>
>> Jeffrey
>>
>>> -----Original Message-----
>>> From: Ali Sajassi (sajassi) [mailto:[e-mail]]
>>> Sent: Monday, February 01, 2016 2:04 AM
>>> To: Jeffrey (Zhaohui) Zhang <[e-mail]>; EXT -
>>> [e-mail] <[e-mail]>; BESS <[e-mail]>;
>>> [e-mail]
>>> Subject: Re: [bess] WG Last Call on draft-ietf-bess-evpn-etree
>>>
>>> Hi Jeffrey,
>>>
>>> Thanks for the review. Your comments helps tighten the draft some more.
>>> I
>>> have updated the draft and will publish it next (rev04). Majority of the
>>> comments were editorial in nature for better clarifications. Since the
>>> existing draft (rev03) reflects the consensus regarding our several
>>> rounds
>>> of discussions where we have taken care of the technical items, it is
>>> consistent with our expectation of not seeing any major issue during the
>>> LC. Please refer to my replies in line.
>>>
>>> Cheers,
>>> Ali
>>>
>>>
>>> On 1/27/16, 5:26 PM, "BESS on behalf of Jeffrey (Zhaohui) Zhang"
>>> <[e-mail] on behalf of [e-mail]> wrote:
>>>
>>>> I was involved in relevant discussions, and have reviewed once more for
>>>> this LC.
>>>>
>>>> I support the publication, but with the following questions/comments.
>>>>
>>>> 2.1 Scenario 1: Leaf OR Root site(s) per PE
>>>>
>>>>    ... If the number of EVIs is very large
>>>>    (e.g., more than 32K or 64K), then RT type 0 as defined in [RFC4360]
>>>>    SHOULD be used; otherwise, RT type 2 is sufficient.
>>>>
>>>> RFC 7153 should be referenced for "Type 2".
>>>
>>>
>>> Done.
>>>
>>>>
>>>> Additionally, why is 32K mentioned? I can understand the 64k part.
>>>
>>> Removed 32K since the example is clear enough with 64K
>>>
>>>>
>>>>    ... the MPLS-encapsulated frames MUST be tagged with an
>>>>    indication of whether they originated from a Leaf AC or not.
>>>>
>>>> Perhaps change the last line to "indication if they originated from a
>>>> Leaf AC"? Packets from a root AC are not tagged with a leaf indication.
>>>
>>> OK. Better yet. It should say ³indication when they originated from a
>>> leaf
>>> AC².
>>>
>>>>
>>>>    Other mechanisms for identifying whether an egress AC is a root or
>>>>    leaf is beyond the scope of this document.
>>>>
>>>> Should "egress" be "ingress" in the above paragraph? Or simply removed?
>>>
>>> Nice catch! It is ³ingress². It is now corrected.
>>>
>>>>
>>>>    ... This Leaf MPLS label is advertised to other PE devices,
>>>>    using a new EVPN Extended Community called E-TREE Extended Community
>>>>    (section 5.1) along with an Ethernet A-D per ES route with ESI of
>>>>    zero and a set of Route Targets (RTs) corresponding to all the leaf
>>>>    ACs on the PE.
>>>>
>>>> Perhaps change the last sentence to "... corresponding to all EVIs that
>>>> have leaf sites on the PE."
>>>
>>> The second to last sentence of section 3.2.1 says the same thing. I
>>> changed this sentence and removed the 2nd to last sentence.
>>>
>>>>
>>>> 3.2.3 BUM traffic originated from a multi-homed site on a leaf AC
>>>>
>>>>    In this scenario, it is assumed that a multi-homed Ethernet Segment
>>>>    (ES) can have a mixed of both leaf and root ACs with each AC
>>>>    designating a subnet (e.g., a VLAN).
>>>>
>>>> I understand that different VLANs on the same ES could be roots or
>>>> leaves. I suppose it's more important to say that for the same vlan,
>>>> different PEs on the same ES must have the same root/leaf designation.
>>>
>>> That¹s given.
>>>
>>>>
>>>> Perhaps the first sentence could be reworded as the following to
>>> capture
>>>> the above point:
>>>>
>>>>    While different ACs (VLANs) on the same ES could have different
>>>>    root/leaf designation (some being roots and some being leaves),
>>>>    the same VLAN does have the same root/leaf designation on all
>>>>    PEs on the same ES.
>>>
>>> That¹s fine. It makes it more clear.
>>>
>>>>
>>>> For the following:
>>>>
>>>>    ... the PEs with Leaf sites perform MAC learning in the
>>>>    data-path over their Ethernet Segments, and advertise reachability
>>> in
>>>>    EVPN MAC Advertisement routes which are imported only by PEs with at
>>>>    least one Root site in the EVI. A PE with only Leaf sites will not
>>>>    import these routes. PEs with Root and/or Leaf sites may use the
>>>>    Ethernet A-D routes for aliasing (in the case of multi-homed
>>>>    segments) and for mass MAC withdrawal per [RFC 7432].
>>>>
>>>> The above seems to contradict with the recommendation in Section 2.2.
>>> If
>>>> the context is the scenario described in section 2.1 then that's fine,
>>>> but the text does not have a clear context.
>>>
>>> Agreed. Updated the section to indicate the context is section 2.1.
>>>
>>>>
>>>>
>>>> 3.3.2 E-Tree without MAC Learning
>>>>
>>>>    The PEs implementing an E-Tree service need not perform MAC learning
>>>>    when the traffic flows between Root and Leaf sites are multicast or
>>>>    broadcast.
>>>>
>>>> I suppose an "only" word should be added at the end of the above
>>> sentence.
>>>
>>> Agreed.
>>>
>>>>
>>>>
>>>>    The fields of the IMET route are populated per the procedures
>>> defined
>>>>    in [RFC7432], and the route import rules are as described in
>>> previous
>>>>    sections.
>>>>
>>>> The route import rules described in previous sections are for MAC
>>> routes,
>>>> not IMET routes. Additionally, those rules may not be recommended, so
>>>> might as well delete the last sentence.
>>>
>>> Changed the last sentence to ³Š, and the multicast tunnel setup criteria
>>> are as described in the previous section.²
>>>
>>>>
>>>> Section 3.3.1 talks about BUM procedures. That is not specific to 3.3.1
>>>> though. Perhaps extract that out to a separate section, and remove the
>>>> BUM text from 3.3.2 as well.
>>>
>>> I think it is OK.
>>>
>>>>
>>>>    The E-TREE Extended Community is encoded as an 8-octet value as
>>>>    follows:
>>>>
>>>>
>>>>         0                   1                   2                   3
>>>>         0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
>>>>
>>> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>>>        | Type=0x06     | Sub-Type=0x04 | Flags(1 Octet)|
>>> |
>>>>
>>> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>>>        |  Reserved=0   |           Leaf Label
>>> |
>>>>
>>> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>>>
>>>> I assume the octect after the flags octet is also reserved=0. Better
>>> mark
>>>> it as "Reserved=0".
>>>
>>> Agreed.
>>>
>>>>
>>>> When it is used with Ethernet A-D per ES route, the leaf flag SHOULD be
>>>> set to 0 but ignored by the receiving routers. Therefore, why not set
>>> it
>>>> to 1 to be consistent the MAC/IP route case?
>>>
>>> Because the flag is used for known unicast traffic and Leaf label for
>>> BUM
>>> traffic. We don¹t want to mix the two.
>>>
>>> Cheers,
>>> Ali
>>>
>>>>
>>>> Thanks.
>>>> Jeffrey
>>>>
>>>>> -----Original Message-----
>>>>> From: BESS [mailto:[e-mail]] On Behalf Of Thomas Morin
>>>>> Sent: Tuesday, January 19, 2016 3:51 AM
>>>>> To: BESS <[e-mail]>; [e-mail]
>>>>> Subject: [bess] WG Last Call on draft-ietf-bess-evpn-etree
>>>>>
>>>>> Hello Working Group,
>>>>>
>>>>> This email starts a Working Group Last Call on
>>>>> draft-ietf-bess-evpn-etree [1] which is considered mature and ready
>>> for
>>>>> a final working group review.
>>>>>
>>>>> Please read the document if you haven't read the most recent version
>>> yet
>>>>> (-03), and send your comments to the list, no later than *February
>>> the
>>>>> 2nd* (2016-02-02).
>>>>>
>>>>> This is not only a call for comments on the document, but also a call
>>> of
>>>>> support for its publication.
>>>>>
>>>>> *Coincidentally*, we are also polling for knowledge of any IPR that
>>>>> applies to draft-ietf-bess-evpn-etree, to ensure that IPR has been
>>>>> disclosed in compliance with IETF IPR rules (see RFCs 3979, 4879,
>>> 3669
>>>>> and 5378 for more details).
>>>>>
>>>>> *If* you are listed as a document author or contributor of
>>>>> draft-ietf-bess-evpn-etree please respond to this email and indicate
>>>>> whether or not you are aware of any relevant IPR.
>>>>>
>>>>> Thank you,
>>>>>
>>>>> Thomas/Martin
>>>>>
>>>>> [1] https://datatracker.ietf.org/doc/draft-ietf-bess-evpn-etree
>>>>>
>>>>> _______________________________________________
>>>>> BESS mailing list
>>>>> [e-mail]
>>>>> https://www.ietf.org/mailman/listinfo/bess
>>>>
>>>> _______________________________________________
>>>> BESS mailing list
>>>> [e-mail]
>>>> https://www.ietf.org/mailman/listinfo/bess
>>
>


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