North American Network Operators Group

Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Re: IPv6 tracking assignments (OSS recommendations)

  • From: Crist Clark
  • Date: Thu Jan 03 18:57:04 2008

>>> Jeroen Massar <jeroen@xxxxxxxxx> 1/2/2008 2:40 PM >>>
Deepak Jain wrote:
> > 
> >> I would think if you find something that tracks IPv6, that's all
> >> you need. You can represent the whole IPv4 space with IPv4-mapped
> >> IPv6 addresses, :ffff:a.b.c.d.
> >>
> > 
> > This is certainly true. Let's not forget that a simple thing that
strips
> > the :ffff: and converts the remaining bits from hex to decimal (at
least
> > visually) would be needed to keep the clue impaired up and running.
:)
> 
> Any application which is visualizing IPv4 adresses using either
> ::ffff:x.x.x.x or ::x.x.x.x is wrong(tm). Those addresses should
never
> ever be shown to the user or used in any way as a textual
representation
> (that includes for instance logfiles, XML files, and other such
things).

I'll freely admit to only dabbling in IPv6 on my home network
and having done a very little bit of nosing around in the KAME
codebase, so I could you give some references for this stance.
Some RFCs or other docs delivered from the mount saying users
are never supposed to see these?

The fact that the RFCs specify special presentation formats
for these addresses kind of just made me assume that they were
meant for humans to see and use. But we all know assumptions
can be way off.

> If you find an application which does this, don't hesitate to kick
the
> coders to fix their stuff.

OK, so, is this,

  $ netstat -an | fgrep ::ffff:
  tcp        0     48 ::ffff:207.88.152.51:22    
::ffff:207.88.153.67:3376   ESTABLISHED 
  $ uname -srvmo
  Linux 2.6.17-1.2142_FC4 #1 Tue Jul 11 22:41:14 EDT 2006 i686
GNU/Linux

On a plain ol' dual stack Linux box living on an IPv4-only network
kosher? Or does kicking need to be done?

BÂinformation contained in this e-mail message is confidential, intended
only for the use of the individual or entity named above. If the reader
of this e-mail is not the intended recipient, or the employee or agent
responsible to deliver it to the intended recipient, you are hereby
notified that any review, dissemination, distribution or copying of this
communication is strictly prohibited. If you have received this e-mail
in error, please contact postmaster@xxxxxxxxxxxxxx