Thanks Dino. Inline.

On Tue, Oct 24, 2017 at 4:59 PM, Dino Farinacci <[email protected]> wrote:
> New rfcdiff.html file enclosed.
>
>>>>>> The same database mapping entries MUST be configured on all ETRs for a
>>>>>> given site.  In a steady state, the EID-Prefixes for the site and the
>>>>>> Locator-Set for each EID-Prefix MUST be the same on all ETRs.
>>>>>>
>>>>>> [AR] Is this still the case when overlapping prefixes and/or
>>>>>> merge-semantics are in place?
>>>>>
>>>>> Response (3).
>>>>>
>>>>> Well, yes. Let me answer with an example. Say there are two xTRs A and B 
>>>>> and they are connecting the LISP site for 10.0.0.0/8. Say 10.1.0.0/16 
>>>>> moves out to another LISP site, a LISP site that is multihomed with xTRs 
>>>>> A’ and B’. Both A’ and B’ need to be configured (i.e. in this case 
>>>>> discover) that the /16 moved into their site.
>>>>
>>>> [AR2] My question was more with regard to the Locator-Set. Let's say
>>>> that two different ETRs serving the same site are registering only
>>>> their own RLOCs and are leveraging on the merge-semantics capability
>>>
>>> There was a decision back when RFC6830 was published to not support this. 
>>> And that we would address it in the NAT-traversal document where the 
>>> use-case required this behavior.
>>
>> [AR3] But this is used today independently of NAT-traversal. It is not
>> uncommon to configure the ETRs with just the interfaces, not the
>> addresses, that should be used for RLOC connectivity. These interfaces
>> will then get dynamically assigned RLOC addresses (e.g. via DHCP) that
>> the ETRs will register to the Map-Server. The deployment is leveraging
>> on the merge capability of the Map-Server rather than on configuring
>> all the RLOC addresses in all the ETRs (since the addresses are
>> unknown at the time of configuration).
>
> So are you suggesting to just remove the paragraph?
>
[AR4] Removing the conflicting text works. Alternatively, we can
update it to reflect actual LISP usage.

>>
>>>>>> When multiple organizations inside of a LISP site are using private
>>>>>> addresses [RFC1918] as EID-Prefixes, their address spaces MUST remain
>>>>>> segregated due to possible address duplication.  An Instance ID in the
>>>>>> address encoding can aid in making the entire AFI-based address
>>>>>> unique.
>>>>>>
>>>>>> [AR] This text is used to introduce the concept of Instance-IDs. I
>>>>>> don't think we should mention private addresses here. Instance ID may
>>>>>> be used even when not private addresses are in place or for purposes
>>>>>> other than possible address duplication. If anything, the private
>>>>>> addresses duplication should be an example only.
>>>>>
>>>>> Response (1).
>>>>>
>>>>> Making a reference to private addresses is actually very important. There 
>>>>> are a lot of container and VMs within cloud provider deployments that use 
>>>>> it. It is probably the most popular use-case of LISP.
>>>>
>>>> [AR2] My intention was to state that we should not tie Instance-IDs to
>>>> the address duplication problem of private addresses. Indeed,
>>>> preventing address duplication is one of the major use-cases for
>>>> Instance-IDs but they are applicable beyond that particular use-case.
>>>
>>> I don’t follow your point, the fact you use EIDs within an IID means the 
>>> EIDs are private to that IID. Regardless if they are RFC1918 addresses or 
>>> registry allocated addresses.
>>
>> [AR3] I would suggest the following text as a replacement for the
>> current paragraph. Feel free to edit as you see fit.
>>
>> "There are several cases where segregation is needed at the EID level.
>> For instance, this is the case for deployments containing overlapping
>> addresses, traffic isolation policies or multi-tenant virtualization.
>> For these and others scenarios where segregation is needed, Instance
>> IDs can be used.”
>
> I would like to hear if the working group agrees to add this text. If by then 
> end of the week I hear no objections or changes, I will include it.
>
[AR4] Sounds good.

>>
>>>>>> An ITR SHOULD only set the E-bit in an encapsulated data packet when
>>>>>> it knows the ETR is
>>>>>> enabled for echo-noncing.  This is conveyed by the E-bit in the
>>>>>> Map-Reply message.
>>>>>>
>>>>>> [AR] There should be probably a mention to merge-semantics and/or
>>>>>> proxy-reply here.
>>>>>
>>>>> Response (3).
>>>>>
>>>>> Why? Merge semantics only apply to Map-Registers. Not the Map-Reply an 
>>>>> ETR sends to an ITR. That is when it conveys it can support echo-noncing.
>>>>
>>>> [AR2] My point was that merge-semantics and proxy-reply may affect the
>>>> E-bit process. For instance, if the MS is merging different
>>>> Map-Registers, (some with the E-bit set, some without), which value
>>>> for the E-bit should the MS return in a Map-Reply?
>>>
>>> It doesn’t because the Map-Server maintains the original individual 
>>> Map-Registers as well. And RLOC-probing causes the E-bit to be specified in 
>>> the Map-Reply by the ETR.
>>
>> [AR3] How about we also include this sentence then?
>>
>> "An ITR can always verify if an ETR supports echo-noncing via sending
>> an RLOC-probe to trigger a Map-Reply.”
>
> How about changing the sentence to:
>
> "This is conveyed by the E-bit in the RLOC-probe Map-Reply message.”
>
[AR4] The new wording looks good, thanks.

Alberto

> The ITR cannot have an option, it must send a RLOC-probe because if a 
> Map-Reply has no E-bit, it would never use echo-noncing.
>
> Dino
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