Re: Who is the design ultimate authority over IPv6? (Re: [spring] WGLC - draft-ietf-spring-srv6-network-programming)

[Brian E Carpenter <[e-mail]>]

On 07-Mar-20 19:13, Fernando Gont wrote:
> On 7/3/20 00:55, Brian E Carpenter wrote:
> [....]
>>>
>>> RFC 4291:
>>>
>>> "2.1.  Addressing Model
>>>
>>>   IPv6 addresses of all types are assigned to interfaces, not nodes.
>>>     An IPv6 unicast address refers to a single interface.  Since each
>>>     interface belongs to a single node, any of that node's interfaces'
>>>     unicast addresses may be used as an identifier for the node."
>>>
>>>
>>> draft-ietf-6man-segment-routing-header-26:
>>>
>>> "4.3.  SR Segment Endpoint Node
>>>
>>>   When an SRv6-capable node receives an IPv6 packet, it performs a
>>>     longest-prefix-match lookup on the packets destination address.  This
>>>     lookup can return any of the following:
>>>
>>>         * A FIB entry that represents a locally instantiated SRv6 SID
>>
>> I'll bet you a beer next time I'm in Melbourne that the implemenations
>> all assign such SIDs to the loopback interface. What else can "locally
>> instantiated" mean in any vaguely Unix-like O/S?
>>
>> What makes me feel upset is using an IPv6-address-shaped object to
>> convey semantics rather than location, 
> 
> Is it segment-routing-header doing tihs, or other subsequent documetns 
> such as network-programming?

RFC 8402 gives these definitions:

>>>    SID: a segment identifier.  Note that the term SID is commonly used
>>>    in place of the term "Segment", though this is technically imprecise
>>>    as it overlooks any necessary translation.
>>> 
>>>    SR-MPLS SID: an MPLS label or an index value into an MPLS label space
>>>    explicitly associated with the segment.
>>> 
>>>    SRv6 SID: an IPv6 address explicitly associated with the segment.

and it is used for routing. But elsewhere in RFC 8402 we find this:

>>>    A segment is often referred to by its Segment Identifier (SID).
>>> 
>>>    A segment may be associated with a topological instruction.  A
>>>    topological local segment may instruct a node to forward the packet
>>>    via a specific outgoing interface.  A topological global segment may
>>>    instruct an SR domain to forward the packet via a specific path to a
>>>    destination.  Different segments may exist for the same destination,
>>>    each with different path objectives (e.g., which metric is minimized,
>>>    what constraints are specified).
>>> 
>>>    A segment may be associated with a service instruction (e.g., the
>>>    packet should be processed by a container or Virtual Machine (VM)
>>>    associated with the segment).  A segment may be associated with a QoS
>>>    treatment (e.g., shape the packets received with this segment at x
>>>    Mbps).
>>> 
>>>    The SR architecture supports any type of instruction associated with
>>>    a segment.

So the reader can decide whether it's a locator, an identifier, or the
label for an open-ended instruction. (I suppose that if an SRV6 node
is capable of supporting many different instructions, it will have
many different SIDs assigned, which IPv6 addressing certainly allows.)

Now I'm not saying that any of this is *bad*. It's innovative, and it isn't
what we traditionally think of as an IP address.

    Brian
>> but as Joel said this went right
>> through the process 
> 
> That ship has sailed, but, if you ask me, I don't think many 6man'ers 
> reviewed the document to the extent we review others.
> 
> 
>> and for reasons that I don't know has been in
>> AUTH48 for 134 days.
> 
> I guess the... AD should know?
> 
> Thanks,
>