Re: RES: ReN: IPv6 tranisition issues

----- Original Message -----
From: "Caitlin Bestler" <[email protected]>
To: <[email protected]>
Sent: Thursday, January 09, 2003 1:14 PM
Subject: Re: RES: ReN: (ngtrans) IPv6 tranisition issues


> On 1/8/03, Rod Van Meter wrote:
>
> >> -----Mensagem original-----
> >> De: Michael R. Cole [mailto:[email protected]]
> >> Enviada em: terga-feira, 31 de dezembro de 2002 09:20
> >> Para: [email protected]
> >> Assunto: Re: ReN: (ngtrans) IPv6 tranisition issues
> >>
> >>
> >> Your claim would also say that a timesharing system with
> >> only 1 public IPv4 address would not work which is what
> >> a cone NAT mimics. That is, a cone NAT fools that public
> >> Internet into thinking that a LAN or other subnet is in
> >> actuality a single machine.
> >
> >That's a gross oversimplification that eliminates the
> >actual problem, so of course it doesn't sound bad when you
> >put it that way.
> >
> >When a computer has a global address, you open a socket
> >and get a port, and you can tell anyone anywhere in the
> >world using any communications medium that they can reach
> >you there.  You can call someone on the telephone and tell
> >them, "My cool new game server is at port 1982 on
> >1.2.3.4!" and it works.  You can send the info via snail
> >mail, and it works.  One friend can tell another friend,
> >and it works.
> >
> Virtually every NAT device I have seen is fully capable of
> statically configuring any port to pass-thru to a specific
> machine. In other words, the single virtual machine can
> offer it service on any port and then use any of its
> component machines to implement that service.
>
> So the statement that a NAT creates a single virtual machine
> is both very accurate, and highlights very precisely its
> limitations.
>
> The next question is how well that Virtual Machine
> communicates internally. There are indeed NATs that have no
> mechanism to dynamically determine the external port
> associated with a given connection, or to dynamically create
> a mapping. That is indeed a poor interface, but to be fair
> it is a poor interface *within* the virtual machine. There
> is nothing wrong with the interface presented to the public
> Internet. The left hand not communicating with the right
> hand is something any Internet host can achieve, whether it
> is composed of a single or multiple machines.
>
> The real point is not that "NAT is evil". There are
> legitimate reasons for presenting a single virtual machine
> to the public network. Rather the issue is that networks are
> forced to use IPv4 NAT to solve other problems such as a
> shortage of public IPv4 addresses and keeping the identity
> of specific machines within a private network confidential.
>
> NAT "breaks" applications when the hosts it is masquerading
> are not actually part of an integrated whole. Properly
> deployed, IPv6 allows each host within a private network to
> have permanent and/or temporary public addresses as
> required.
>
> I believe NAT bashing is counter-productive to IPv6
> deployment. Too many comments make it sound as though IPv6
> advocates believe that only fools would use a NAT. A lot of
> non-fools had very valid reasons to deploy NAT. The best way
> to convince them that IPv6 offers better solutions to those
> problems is by starting with acknowleding their legitimate
> problems and understanding why they chose to deploy NATs in
> the first place.
>
> Caitlin Bestler
> http://asomi.com/CaitlinBestler/
>

Thank you very much for explaining why one of the NAT+gateway packages that
I have tried works so well (that I am tempted to buy it) and the commercial
version has features that should NOT be omitted from any connectivity
software.

However, with only a 33.6 Kbps dialup connection I cannot justify buying a
package yet. I can only justify playing around with a package for the 30-day
trial period.