Re: Fwd: New Version Notification for draft-hinden-ipv4flag-00.txt

[Fernando Gont <[e-mail]>]

HI, BOb,

Comments/questions:

* How about the case in which a user employs an IPv4-only printer on an
IPv6-only network?

* Does this document imply that IPv6 is bootstrapped first than, or in
parallel of, IPv4?

* If IPv4-has already been bootstrapped, would 4=1 still cause the node
to disable IPv4?

* If 4=1, but later 4=0, shuld that transition of the 4 bit trigger IPv4
configuration?


* Sec cons: see RFC7113 -- it seems that still the current state of
affairs for many implementations (unfortunately).


Thanks!

Cheers,
Fernando




On 11/17/2017 02:42 PM, Bob Hinden wrote:
> Hi,
> 
> Brian and I took a cut a defining an IPv4 Availability Flag for IPv6 ND
> Router Advertisements.  From the Introduction:
> 
>    Hosts that support IPv4 and IPv6, usually called dual stack hosts,
>    need to work on IPv6 only networks.  That is, a link where there are
>    no IPv4 routers and/or IPv4 services.  Monitoring of IPv6-only
>    networks, for example at the IETF 100 meeting in Singapore, shows
>    that current dual stack hosts will create local auto-configured IPv4
>    addresses and attempt to reach IPv4 services.  A mechanism is needed
>    to inform hosts that there is no IPv4 support and that they should
>    turn off IPv4.
> 
>    Because there is no IPv4 support on these links, the only way to
>    notify the dual stack hosts on the link is to use an IPv6 mechanism.
>    An active notification will be much more robust than attempting to
>    deduce this state by the lack of IPv4 responses or traffic.
> 
>    IPv4-only hosts, and dual-stack hosts that do not recognize the new
>    flag, will continue to attempt IPv4 operations, in particular IPv4
>    discovery protocols typically sent as link-layer broadcasts.  This
>    legacy traffic cannot be prevented by any IPv6 mechanism.  The value
>    of the new flag is limited to dual-stack hosts that recognize it.
> 
> We were originally thinking it would be an April 1 submission, but after
> reading the discussion on the IPv6 list, we decided it makes sense as a
> real submission :-)
> 
> Please review and comment.
> 
> Thanks,
> Bob and Brian
> 
> 
>> Begin forwarded message:
>>
>> *From: *[e-mail] <mailto:[e-mail]>
>> *Subject: **New Version Notification for draft-hinden-ipv4flag-00.txt*
>> *Date: *November 17, 2017 at 2:36:31 PM GMT+8
>> *To: *"Robert M. Hinden" <[e-mail]
>> <mailto:[e-mail]>>, "Robert Hinden" <[e-mail]
>> <mailto:[e-mail]>>, "Brian Carpenter"
>> <[e-mail] <mailto:[e-mail]>>
>>
>>
>> A new version of I-D, draft-hinden-ipv4flag-00.txt
>> has been successfully submitted by Robert M. Hinden and posted to the
>> IETF repository.
>>
>> Name:draft-hinden-ipv4flag
>> Revision:00
>> Title:IPv6 Router Advertisement IPv4 Availability Flag
>> Document date:2017-11-17
>> Group:Individual Submission
>> Pages:5
>> URL:
>>            https://www.ietf.org/internet-drafts/draft-hinden-ipv4flag-00.txt
>> Status:         https://datatracker.ietf.org/doc/draft-hinden-ipv4flag/
>> Htmlized:       https://tools.ietf.org/html/draft-hinden-ipv4flag-00
>> Htmlized:
>>       https://datatracker.ietf.org/doc/html/draft-hinden-ipv4flag-00
>>
>>
>> Abstract:
>>   This document specifies a Router Advertisement Flag to indicate that
>>   there is no IPv4 service on the advertising router.  This document
>>   updates RFC5175.
>>
>>
>>
>>
>> Please note that it may take a couple of minutes from the time of
>> submission
>> until the htmlized version and diff are available at tools.ietf.org
>> <http://tools.ietf.org>.
>>
>> The IETF Secretariat
>>
> 
> 
> 
> --------------------------------------------------------------------
> IETF IPv6 working group mailing list
> [e-mail]
> Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6
> --------------------------------------------------------------------
> 


-- 
Fernando Gont
e-mail: [e-mail] || [e-mail]
PGP Fingerprint: 7809 84F5 322E 45C7 F1C9 3945 96EE A9EF D076 FFF1