questions about interfaces

[David Cuthbert]

Bill Hacker wrote:
David Cuthbert wrote:
Heh... imagine if the loopback interface actually required hardware.
Imagine?  'Remember when' you mean...

It exists because there was a time when hardware *was* required, and one 
did not always have arms long enough...
I remember using (and still use) this for modems and serial ports (doing 
local and remote loopback tests), but never in the context of an IP 
loopback connection.  This is probably because all of my experience with 
IP/TCP/UDP has been on top of a OS+stack that someone else wrote and 
debugged, running on hardware that wasn't too terribly esoteric.