I don't want to change it (as if I could!), my purpose was to point out
that our current network is the sum of our mistakes, not the network
equivalent of the Mount Sinai tablets.
no disagreement there. but the original mistakes in TCP/IP were more-or-less
designed to work together. when people start deploying their own mistakes
in an ad hoc fashion, and when multiple mistakes get added concurrently,
not only do they break things that assumed that the only mistakes in the
network were those originally designed-in, the combined effect of those
new mistakes is far worse than the effect of any of them taken individually.
Keith
p.s. I will also argue that the complexities of adding a separate
application-level identifer and doing without the source address,
are such that had this been done in the original TCP/IP design,
it would have had a much more difficult time getting deployed
in the first place.