[comp.protocols.tcp-ip] What good is the 127.x.x.x network?

csu@alembic.acs.com (Dave Mack) (05/27/91)

Is it my imagination, or is there an entire Class A network (127.x.x.x)
that is essentially unusable? Is anybody out there using it for
anything besides loopback?

-- 
Dave Mack

smeg@laguna.uucp (Maarten Koning) (05/28/91)

In article <1991May26.170543.7991@alembic.acs.com> csu@alembic.acs.com (Dave Mack) writes:
>Is it my imagination, or is there an entire Class A network (127.x.x.x)
>that is essentially unusable? Is anybody out there using it for
>anything besides loopback?
>
>-- 
>Dave Mack

I have an OS simulation that runs under UNIX at user level as a single
process.  This simulator has full IP networking capabilities and when
it starts up, it dynamically allocates an IP address out of the 127
network. It also adjusts the hosts (in my case, a Sun 4/65) routing table
to route to a special networking interface that provides a file descriptor
interface to a user level process.  The simulator sends and receives
these IP packets using good old read & write to /dev/ip.

Anyway, the 127 net is handy when you need an IP address that never
leaves your machine on a real (hardware) interface.

Maarten Koning
--
//include1 pgm=disclaimer,parm='my opinions only'
Maarten Koning | Internet:  smeg@bnr.ca        | Phone: (613) 763-8796
BNR Ltd.       |     UUCP:  smeg@bigsur.UUCP   | FAX:   (613) 763-2626