Re: [BEHAVE] Learning IPv6 translator's prefix - draft-wing-behave-learn-prefix-03

[Chen Gang <[e-mail]>]

Hello Dan,

2009/7/21 Dan Wing <[e-mail]>

> > On 2009-07-20 22:58, Chen Gang wrote:
> > > I guess that my point hasn't been clarified enough,
> > >
> > > What I am saying is that NAT64 draft is based on the Ipv6 only host,
> > > But the question here is how could "http://1.2.3.4" be
> > > processed by network stack,
> > > will IPv4 socket api be called or will IPv6 socket api be called.
> >
> > Firstly, should we really be spending effort on this problem? What's
> > wrong with an error response to the user? Address literals
> > are supposed
> > to be for diagnostic use only. "No IPv4 available" would be
> > an appropriate diagnostic message.
>
> IPv4 address literals in URLs are an obvious use of IPv4 address
> literals, but I agree they are the most likely to resolve themselves.
> As recently as last month I was still seeing IPv4 address literals as
> results from various search engines; if I was IPv6-only and I lacked
> BIA (RFC3338) or BIS (RFC2767), I would be out of luck.  We do need
> *some* way of solving that.  Perhaps, as I believe you are suggesting,
> the solution is "do BIA" or "do BIS", rather than encouraging solving
> the problem in the application.


=> "do BIA", "do BIS" and "upgrading applicaiton" are three ways to resolve
the problems.
But there is not enough incentive to upgrade existing IPv4 applications. For
host stack, it could be possible to be modified to accomodate IPv4
applicaition when operators strat to customize user's terminals. Therefore,
the probability of  convitional IPv4 app on a "upgraded IPv6 host"  might be
higher than "upgraded IPv4 application" on a normal IPv6 host.

I would like to propose one more application which can benefit knowing the
IPv6 prefix:
   ....
*   o  A conventional IPv4 applciation installed on a IPv6 host, on which
host-based translator functionalities are performed to make IPv4 application
accomodate IPv6 stack.*

Thanks for the discussion.

BRs

Chen Gang



>
>
> There are other applications that commonly use IPv4 address literals.
> SIP and RTSP use IPv4 address literals almost exclusively in their
> SDP (which describes the IP addresses and ports for the media path).
> For those protocols, it makes little sense to rely on DNS to say
> 128-7-8-9.comcast.net rather than just 128.7.8.9.  I believe XMPP
> works similarly and uses IPv4 address literals.
>
> > Secondly, as others have observed, RFC3338 documented a solution 7
> > years ago, to which we need to add a way to determine the correct
> > v6 prefix to use. The same goes for RFC2767.
>
> -d
>
>


-- 
陈刚
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