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Re: Where NAT disenfranchises the end-user ...

  • From: bmanning
  • Date: Fri Sep 07 13:53:38 2001


Sez you.  As you design you app, please consider how many NATs the
packets must traverse and what each may do to your packets while in
flight (without telling you squat) before they reach the intended 
destination (and for that matter, how do you tell when you've arrived?)

NAT designers mess with MTU, headers, and even the data.  By the
time the packets "reach" the intended receipient, they're not even
mine anymore.  But that is a comforting thought. Plausable Deniability.
"No UrHonour, I never sent that. It did not come from my machine."

Again, NAT is a tool.  Where it makes sense to share fate, impose 
random policy, and (oh yeah) save some slots in Friend Bushes routing
table, NAT is your friend.

:Random Ob:
Flip NAT over, use RFC 1918 space as the "global" address space and
run everything else "inside" as private space.  This may be the "poison pill"
that solves the apparent routing table problems if the IRTF & IESG can't
solve the problems for us in time.

--bill (needing more sleep)


> It seems a pretty simple argument to me.
> 
> Do I want as many people using (and maybe _buying_, what a concept!) 
> my app as possible with the least amount of network clue and setup 
> headaches, or do I want to eliminate most of the corporate, SOHO, 
> cable, DSL, Linux population because I cant be bothered to develop my 
> app to be NAT-friendly.
> 
> Duh!
> 
> All the previous times this discussion has arisen here, I have 
> concluded that "real" IPs should only be owned and used by folks with 
> clue, everyone else gets a NATed IP. Discuss.
> 
> jm
> 
> >  > > |> True...  neither does a well-firewalled LAN.
> >>  >
> >>  > There is a substantial difference between broken access and controlled
> >>  > access.
> >>
> >>  Yes, but there are plenty of apps that will not work if you do not leave
> >>  open large, arbitrary ranges of udp ports.  This is fundamentally
> >>  incompatible with most sane firewalls.  Or NAT.
> >>
> >>  Why write a protocol that way?  Just to prove NAT sucks?
> >>
> >>  Charles
> >
> >
> >	No, because they were either written before NAT existed and
> >tried hard to conform to the end2end principles of Internet Architecture
> >or they were written after NAT existed and tried hard to conform to the
> >end2end principles of Internet Architecture.
> >
> >	NAT violates the end2end principles of the Internet Architecture
> >by placing one or more policy abstraction layer(s) between the endpoints.
> >
> >	That said, NAT is a tool in the tool box.  I'd like to think that
> >its worth the effort to try and recover true end2end.
> >
> >--bill
> 
> jon_mansey@verestar.com                      Chief Science Officer
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