Understanding IP class range.

[parabellum7 at yahoo.com]

 > Very nice Kenn!!

Thanks! Good to revisit this stuff from time to time, rattle the old brain-box and make sure there's still something in there!  :)

 
> Ok so if I had 192.168.1.0/25 the range would be 192.168.1.0 -  192.168.1.127

Yes.


 
> /26 would be 192.168.1.0 - 192.168.1.192 ?  or is it 192.168.1.0 - 192.168.1.64 ?

/26 would yield 192.168.1.0 - 192.168.1.63


 
> Not sure how to make a net mask out of 192.168.1.0/25 -  would it be  255.255.255.128?

Yes


 
The calculator Daniel provided is good:

http://www.subnet-calculator.com/cidr.php


The one kitepilot provided is also nice because it illustrates the full binary. 

http://jodies.de/ipcalc 


They're neet to play with and better than others I've seen. I've bookmarked both, thanks for sharing these resources. 


--Kenn