[ih] What is the origin of the private network address 192.168.*.*?

[Craig Partridge]

> The excellent Q&A site Server Fault has an interesting question, which
> may interest some persons here. Answer directly on Server Fault (you
> need to log in with an OpenID identifier) or post here and I'll write
> it back to Server Fault.
> 
> http://serverfault.com/questions/64013/what-is-the-origin-of-the-private-netw
> ork-address-192-168
> 
> I had a smart (but non-technical) user ask me today:
> 
> Why did they pick 192.168.. for a private network address?
> The only answer I could come up with is because 192 = 11000000 in binary. And
>  168 is 10101000 in binary. Both of which are kind of cool looking.
> 
> Is there a real historical reason for that particular choice of numbers? Why 
> not 127.127..? Or 128.128..?


Dunno, though the fact it is what used to be a class C address is a hint
but I think the convention was established after we went to CIDR.

> Similar question for 10.0.0.0 and 172.16.0.0

10.0.0.0 is easy.  For folks who needed LARGE private networks the only
large space available by the early 1990s was the old ARPANET network
number (the ARPANET was net 10 and was decommissioned around 1991).

********************
Craig Partridge
Chief Scientist, BBN Technologies
E-mail: craig at aland.bbn.com or craig at bbn.com
Phone: +1 517 324 3425