In this case the benefit to running NAT on my home network is that it saves
me $50 per month in ISP fees, means I have wireless service to the whole
house and means that guests can easily connect.
one immediate benefit to my running IPv6 on my home network is that I
can access any of my machines from anywhere else on the network (via
6to4), as long as I'm not behind a NAT. my home network also has a v4
NAT, so it's not as if they're mutually exclusive.
I have never seen a coherent, rational argument as to why the network
numbering on my internal network should be the same as the network numbering
on the Internet.
obviously you've never tried to write a distributed application in a
NATted network. and presumably you never tried to do anything with UUCP
mail (which had naming conflicts) or a large DECnet (which had address
conflicts). the problems are immediately obvious to those of us who
have had to deal with those disasters.
in brief: one reason is so that apps can have the same view of the
network regardless of whether they're hosted on your internal network,
or on an external network, or on a combination of the two. it's MUCH
simpler if apps don't have to worry about the fact that host A has
address A1 from network X and address A2 from network Y. particularly
since in a network with scoped addresses, hosts don't really have any
way of knowing which network they're on.
there are other reasons also: routing, coherent network management, DNS
consistency. a network with scoped addressing is like a city where all
of the streets have the same name. it becomes pretty difficult to navigate.
People will still want to do NAT on IPv6.
true. people do all kinds of evil things that break the net. our
protocols will only work to the extent that people follow the
specifications. when people start breaking things, the protocols and
applications start failing. NAT is a good example.
in ipv6, we can provide better ways of solving the problems that people
think they're solving with NATs. if we fail to do that, or if people
insist on using NATs anyway, we're screwed. but that's not a reason to
give up without trying.
either do something to help or get out of the way.
Ietf mailing list