cb.list6 wrote:
I think there is something here that is interesting, and that is the
interplay between paper design, evolution, and ultimately the emergent
complex dynamical system we call the internet ... which is almost
completely zero compliant to the e2e principle. Not that e2e is the wrong
principle, but ipv4 could not support it as of 10+ years ago.
As long as a NAT box is directly connected to the Internet
and is UPnP capable, which is the case at my home, hosts
behind it can enjoy full end to end transparency (PORT
command of FTP works), if hosts' IP and transport stack is
modified a little.
Hence, nearly
every internet node is behind a stateful device (cpe or cgn nat)
That is not a problem if state of the device is known to
the end, because IP and transport stack of the end
can reverse the translation.
See draft-ohta-e2e-nat-00.txt for details.
or server
load balancer. There is also widespread disbelief in how dns operates in
the real world (not everyone gets the same answer).
It has nothing to do with the end to end transparency.
If operators of the servers think any server is fine, it is not
a problem.
Masataka Ohta