[ih] History of 127/8 as localhost/loopback addresses?

[gaylord at dirtcheapemail.com]

On Sat, Jan 2, 2021, at 10:52 AM, Carsten Bormann via Internet-history wrote:
> On 2021-01-02, at 14:40, Craig Partridge via Internet-history 
> <internet-history at elists.isoc.org> wrote:
> > 
> > loopback
> 
> I think it is an unfortunate artifact of naming the localhost address 
> “loopback” that it is easily confused with actual loopback functions.  
> The latter are meant to test a line or path by having the remote end 
> loop back the traffic, and I’m sure that some form of this was used in 
> diagnosing most reasonably operating networks.  Information takes an 
> actual loop (which happens to coincide with the “local loop” in many 
> cases) from one end of a line/path to another end and back.

I don't think it's unfortunate actually. There is a true "local loopback" concept, much closer than the "local loop" which is (e.g. on a T-1) a physical loop directly on the local network interface. This serves to ensure the local interface is working correctly, so has a very reasonable analogy to the loopback network interface, confirming the operation of the local networking stack. 

Clark