Protocol Wars
I wish we could start over and redesign everything from Ethernet up to TLS with the lessons we now understand.  So many layers could be merged, security could be so much easier, IP addressing hassles could be unnecessary.<p>But all the stuff that seems obvious now couldn&#x27;t have been learned without
the decades of kind of terrible hackery that is OSI and the associated awful stuff like DNS.<p>I&#x27;m not sure what the moral of that story is or how anything could have been done any better.  Maybe the software APIs could have been less coupled to the actual protocol, they could have designed things so app code had to be agnostic to the number of bits in an IP address, etc.