>   All you need to do to separate what from where is have two numbers in
 > each header, one used for routing and the other for host identification.

    (This bit of history predates me, but a look at the C headers
seems to confirm this).

    Isn't this what XNS does (circa late 1970s)?  Since prior art
seemed to exist that predated IP, why did the IP designers collapse
into one "what & where" identifier?  Did they have reason to not to
seperate them?

    Anyway, just thought I'd inject some perspective into this.