Re: Fwd: Confirmation to advance: draft-ietf-6man-ipv6only-flag-05

[Alexandre Petrescu <[e-mail]>]

Le 08/05/2019 à 00:23, David Farmer a écrit :
> Whoops, I lost the list somehow.
> 
> ---------- Forwarded message ---------
> From: *David Farmer* <[e-mail] <mailto:[e-mail]>>
> Date: Tue, May 7, 2019 at 5:13 PM
> Subject: Re: Confirmation to advance: draft-ietf-6man-ipv6only-flag-05
> To: Manfredi (US), Albert E <[e-mail] 
> <mailto:[e-mail]>>
> 
> 
> 
> 
> On Tue, May 7, 2019 at 4:26 PM Manfredi (US), Albert E 
> <[e-mail] <mailto:[e-mail]>> wrote:
> 
>     On Mon, 29 Apr 2019, Ole Troan wrote:
> 
>      > At the 6man meeting at IETF 104 in Prague there was support to
>     close the working group last call and advance
>      > draft-ietf-6man-ipv6only-flag-05 to the IESG.
>      >
>      > This call is to confirm that decision on the mailing list.
>      >
>      > Please give objections and comments to this decision to the
>     mailing list, by 2019-05-13.
> 
>     I've not changed my mind on this. The flag seems unnecessary, and if
>     anything, can cause confusion and problems. It seems to have been
>     motivated by people wanting to see what it would be like to get all
>     IPv4 users off the network, at an IETF meeting, and then people have
>     been trying to make the case that it would be generically useful.
> 
>     There are other ways of sunsetting IPv4 if a network wants to,
>     exactly the same as any number of older network protocols have been
>     obsoleted, never needing any new explicit flag for the purpose. And
>     I would way prefer for equipment vendors themselves, such as
>     smartphone vendors, to create their own heuristics, if they feel
>     that IPv4 is so wasteful of battery power. The onus should be on
>     them, IMO, not on the IETF, and certainly not on other users of the
>     network who might not know or pay attention to that flag.
> 
>     The KISS principle holds. Only add complications if it's essential.
> 
> 
> The two alternatives to this flag I've heard discussed are;
> 
> 1. Layer 2 filtering of Etherthypes 0x0800 and 0x0806

Layer-2 filtering on ethertype is a great idea.  I would concur.

But on cellular links there's no ethertype.  It's what they call a PDP type.

(this is not a support neither not support of  the draft; my own idea of 
the draft is that because is covered by IPR it is basically killed).

Alex

> 2. RFC2563 to signal host to not use Link-local IPv4
> 
> The problem is, these two options are incompatible with each other. You 
> can either block IPv4 traffic or signal the host that not to use 
> Link-local IPv4, you really can't do both at the same time.
> 
> I just had a thought, what if the host behavior for the flag was changed 
> to be more like the behavior specified for RFC2563?
> 
> In the presence of the flag, a host MAY attempt DHCPv4 a limited number 
> of times, but MUST NOT perform Stateless Auto-Configuration of an IPv4 
> address and MUST NOT perform any service discovery (such as mDNS) unless 
> it receives a unicast IPv4 address from DHCPv4 server or relay on the 
> network.
> 
> This way a Rogue RA with this flag set is much less dangerous than a 
> Rouge DHCPv4 server and doesn't directly impede IPv4 internet access. It 
> would impede Link-local IPv4, but only if there is not a functioning 
> DHCPv4 server or the attacker can also block the DHCPv4 process in 
> addition to announcing a rogue RA with the flag set.
> Would that be acceptable?
> 
> -- 
> ===============================================
> David Farmer Email:[e-mail] <mailto:[e-mail]>
> Networking & Telecommunication Services
> Office of Information Technology
> University of Minnesota
> 2218 University Ave SE        Phone: [phone]
> Minneapolis, MN 55414-3029   Cell: 612-812-9952
> ===============================================
> 
> 
> -- 
> ===============================================
> David Farmer Email:[e-mail] <mailto:[e-mail]>
> Networking & Telecommunication Services
> Office of Information Technology
> University of Minnesota
> 2218 University Ave SE        Phone: [phone]
> Minneapolis, MN 55414-3029   Cell: 612-812-9952
> ===============================================
> 
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