"Bernard D. Aboba" wrote:
And of course, as the address space continues to run out it is likely
that enterprise and perhaps even ISP NAT deployment will increase
substantially over the next few years.
What is worth thinking about is what this will imply for the future
internet architecture. It is one thing to address issues brought up by a
single well functioning NAT within the same administrative domain. It is
another thing to deal with multiple layers of perhaps not so well
implemented NATs which may not even support tunneling of IPv6.
And that is where we appear to be headed over the next few years.
More than an year ago I commented here that NATs can help IPv6
interoperate... so, they are by definition, useful. I also suggested we
don't yet have a "NAT model", in engineering sense, where a model
fits in a larger model and so on. All we have is a "NAT hack", but this
does not mean that NATs are hacks (though they sort of rhyme).
Technically, a NAT box is used to interconnect two (or more) independent
networks so that hosts in the networks can communicate with one another
*without any change* to the respective networks, usually by means of a
programmable device that performs automatic address translation in
transmission and/or address and name translation in reception for each
formatted message. This is benefitial not only to provide Internet routing to
near unlimited addresses in private networks but also for address hidding,
privacy and flexibility.
So, maybe this is what the market really wants -- a multiple-protocol Internet,
where tools such as NAT boxes for firewalling, privacy, address extension and
IPv4/IPv6 interoperation will be needed ... and valued. The lesson is that the
Internet does not have to be a homogenous network, it can be a heteregenous
network with IPv4/NAT/IPv6. Since a heterogeneous network can use local
solutions for local problems, I believe Internet users will continue to prefer
local flexibility.
Comments?
Cheers,
Ed Gerck