Subject: Re: [v6ops] New Version Notification for draft-palet-v6ops-ipv6-only-02.txt

From: JORDI PALET MARTINEZ <[email-masked]>
Date: Wed, 01 Nov 2017 13:01:53 +0100

When I was updating this document from v02 to v03, I was considering including the definition of IPv4-only.

However, being the document a terminology about IPv6-only, I decided that including IPv4-only doesn’t make too much sense and can be inferred from the IPv6-only definition and the rest of terms in the document.

In fact, if we agree to include it, I think it will be something like the same as we have for IPv6-only, so:
- IPv4-only network
- IPv4-only WAN/access
- IPv4-only LAN
- IPv4-only host/router
- Transitional IPv4 host/router

Yes, I know, I can just define IPv6-only “*” (wildcard), and IPv4-only *, and make a 1 page ID. But not being more specific is the problem I’m trying to resolve: the lack of clarity when we speak about this.

Thoughts?

Regards,
Jordi

-----Mensaje original-----
De: George Michaelson <[email-masked]>
Responder a: <[email-masked]>
Fecha: miércoles, 18 de octubre de 2017, 0:24
Para: Fred Baker <[email-masked]>
CC: JORDI PALET MARTINEZ <[email-masked]>, "<[email-masked]>" <[email-masked]>
Asunto: Re: [v6ops] New Version Notification for draft-palet-v6ops-ipv6-only-02.txt

    Not that anyone doesn't understand this, but a 'network' could quite
    possibly "not support" IPv4 and still have IPv4 packets on it. So, you
    can expect to see ARP. you can expect to see DHCP requests. You can
    even see half-open TCP.
    
    Diagnostically, the state of being 'IPv6 only' doesn't mean there is
    no IPv4 packet types on the wire. it just means they aren't being
    supported, carried forward, responded to by deliberate deployment
    choices. No router is being proffered, no DNS service is being
    proferred.
    
    But if somebody turns up an IPv4 DHCP server, responds to ARP, and
    offers a default route, You are not necessarily blocking them.
    
    An IPv4 *blocked* network would be one, which uses lower level (layer
    2) switch or other methods to refuse to forward frames which carry
    IPv4 and associated (ARP) traffic.
    
    Thats different.
    
    -G
    
    On Wed, Oct 18, 2017 at 4:06 AM, Fred Baker <[email-masked]> wrote:
    >
    >
    >> On Oct 17, 2017, at 10:43 AM, JORDI PALET MARTINEZ <[email-masked]> wrote:
    >>
    >>    - I think a short "Definition of IPv4-only" would be useful to include.
    >
    > A little rumination in context. Hats off.
    >
    > To me, an IPv4-only thing is a thing that can only communicate using IPv4. That would be true of an IPv4-only host, an IPv4-only LAN, or an IPv4-only network. In each case, there is a question of perspective: if an ISP only offers a subscriber IPv4 addresses or prefixes, then the subscriber is IPv4-only from the ISP's perspective, even though it might be using something else internally or when communicating via some other connectivity. If we are speaking from the perspective of the host itself, it might mean that it is perfectly capable of communicating using something else, but it has only been provisioned with an IPv4 address, or it can communicate with peers on its LAN using something else, but the router is IPv4-only, and so when it communicates with devices beyond the router (or they try to communicate with it), IPv4 is the only thing that works.
    >
    > So, suggested text:
    >
    > IPv4-only: only capable of or provisioned to communicate using IPv4. The description is always from a perspective, whether the perspective of a host or network seeking to communicate, or that of another host or network describing a communication peer.
    >
    > _______________________________________________
    > v6ops mailing list
    > [email-masked]
    > https://www.ietf.org/mailman/listinfo/v6ops
    >

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---

From: Azael Fernandez Alcantara <[email-masked]>
Date: Fri, 3 Nov 2017 00:17:09 -0600

Hi all,

I also agree to include the other mentioned IPv4-only definitions that 
would help at the same the time to clarify the IPv6-only definitions.

But in this were the case, maybe it would be better to change the title of 
the draft with something like "IPv6-only / IPv4-only Terminology 
Definitions" , in order not to have a second draft with a title "IPv4-only 
Terminology Definition" that would not be good to have it in a separate 
document.

BEST,
SALUDOS,
_______
Azael

On Wed, 1 Nov 2017, JORDI PALET MARTINEZ wrote:

> However, being the document a terminology about IPv6-only, I decided 
> that including IPv4-only doesn’t make too much sense and can be inferred 
> from the IPv6-only definition and the rest of terms in the document.
>
> Yes, I know, I can just define IPv6-only “*” (wildcard), and IPv4-only 
> *, and make a 1 page ID. But not being more specific is the problem I’m 
> trying to resolve: the lack of clarity when we speak about this.
>
> Thoughts?
>
> Regards,
> Jordi
> 
>

---

From: Fred Baker <[email-masked]>
Date: Fri, 3 Nov 2017 11:13:45 +0400

Hats off...

From my perspective, whether something is mumble-only is a statement made about it by another party, asserting that they can only communicate with it using mumble (and BTW, personally I would define {IPv4|IPv6}-only, not IPv4-only and separately IPv6-only). I don't generally know why I can only communicate with something using a given protocol, only that it is the case. For example, www.ipv6.example.com is an IPv6-only service if it has a AAAA record and not an A record, even if the computer in question has an IPv4 address. It is indistinguishable from a system that has only an IPv6 address from the perspective of an observer. In general, it is difficult to enforce the policy that a network be {IPv4|IPv6}-only, because the hosts in it can generate {IPv6|IPv4} link-local addresses and communicate using them. I could imagine a network administrator asserting that his or her network is mumble-only by policy, only to discover hosts communicating within it using protocols the sysadmin didn't intend.

> On Nov 1, 2017, at 4:01 PM, JORDI PALET MARTINEZ <[email-masked]> wrote:
>

---

From: Lee Howard <[email-masked]>
Date: Fri, 03 Nov 2017 10:51:35 -0400

>Hats off...

Similarly unhatted.

>
>From my perspective, whether something is mumble-only is a statement made
>about it by another party, asserting that they can only communicate with
>it using mumble (and BTW, personally I would define {IPv4|IPv6}-only, not
>IPv4-only and separately IPv6-only).

As a principle, that makes sense to me. But when I dig into it, I can’t
support it.
If you have no IP route to me, that doesn’t mean I don’t support IP.
If I only have IPv6 on all interfaces, and you only have IPv4 on all
interfaces, but you can reach me over IPv4 through some transition
mechanism, does that mean that you no longer fit the description of
IPv4-only and I am not IPv6-only?
If you can reach some hosts via transition mechanisms provided by their
ISP or network operator (etc.), but you can’t reach other hosts that only
have IPv6 because there is no transition mechanism, how would we describe
you? 

>I don't generally know why I can only communicate with something using a
>given protocol, only that it is the case. For example,
>www.ipv6.example.com is an IPv6-only service if it has a AAAA record and
>not an A record, even if the computer in question has an IPv4 address. It
>is indistinguishable from a system that has only an IPv6 address from the
>perspective of an observer. In general, it is difficult to enforce the
>policy that a network be {IPv4|IPv6}-only, because the hosts in it can
>generate {IPv6|IPv4} link-local addresses and communicate using them. I
>could imagine a network administrator asserting that his or her network
>is mumble-only by policy, only to discover hosts communicating within it
>using protocols the sysadmin didn't intend.

There’s a difference between a descriptive definition and a prescriptive
definition. We can assert that “IPv4-only host” is a description of a
device that only has IPv4 addresses configured on it, and that description
can be used until someone discovers that the device has IPv6 link-local
addresses. That doesn’t mean the description is wrong, just that it turns
out not to apply.

Lee

>>> To me, an IPv4-only thing is a thing that can only communicate using
>>>IPv4. That would be true of an IPv4-only host, an IPv4-only LAN, or an
>>>IPv4-only network. In each case, there is a question of perspective: if
>>>an ISP only offers a subscriber IPv4 addresses or prefixes, then the
>>>subscriber is IPv4-only from the ISP's perspective, even though it
>>>might be using something else internally or when communicating via some
>>>other connectivity. If we are speaking from the perspective of the host
>>>itself, it might mean that it is perfectly capable of communicating
>>>using something else, but it has only been provisioned with an IPv4
>>>address, or it can communicate with peers on its LAN using something
>>>else, but the router is IPv4-only, and so when it communicates with
>>>devices beyond the router (or they try to communicate with it), IPv4 is
>>>the only thing that works.
>>> 
>>> So, suggested text:
>>> 
>>> IPv4-only: only capable of or provisioned to communicate using IPv4.
>>>The description is always from a perspective, whether the perspective
>>>of a host or network seeking to communicate, or that of another host or
>>>network describing a communication peer.
>>> 
>> This electronic message contains information which may be privileged or
>>confidential. The information is intended to be for the exclusive use of
>>the individual(s) named above and further non-explicilty authorized
>>disclosure, copying, distribution or use of the contents of this
>>information, even if partially, including attached files, is strictly
>>prohibited and will be considered a criminal offense. If you are not the
>>intended recipient be aware that any disclosure, copying, distribution
>>or use of the contents of this information, even if partially, including
>>attached files, is strictly prohibited, will be considered a criminal
>>offense, so you must reply to the original sender to inform about this
>>communication and delete it.
>> 
>> 
>>