My chart says that 192.x.x.x to 223.x.x.x are Class C addresses, yet 192.168.0.0 (with sub msk 255.255.0.0)...

acts like a Class B address; leaving the last two octets to assign hosts to. Albiet by stealing 3 bits from the host part.





Am I the only one to find this confusing, maybe even misleading?





Are there many 'rules of thumb' you can't point me to when performing subnet mask calculations?





Thanks in advance for your answers.

My chart says that 192.x.x.x to 223.x.x.x are Class C addresses, yet 192.168.0.0 (with sub msk 255.255.0.0)...
Well in a Class C address 255.255.255.x is the correct subnet range! 255.255.x.x is a Class B range so of course the "C" addresses when used with the B subnet will act like a "B" class Its the subnet range that determines the CLASS behavior.





Class A addresses can have a mask bit of 8


Class B addresses can have a mask bit of 16


Class C addresses can have a mask bit of 24


(That doesn't mean you can't use a class A or B address with a mask bit of 24 - it means you then only have 254 hosts available in that subnet range! How else do you "divide them up"?)





Here is a simple to use Calculator that will help the understanding


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


Click the A , B, C at the top to see what subnet and mask bits are available by CLASS. You can even use 255.0.0.0 with an IP of 192.x.x.x but it is not a correct setting and this particular calculator will show that and force an IP change to fit.





The other great place to learn this is


http://learntosubnet.com





You as the admin have to use the correct settings for the "correct" results.
Reply:192.x.x.x to 223.x.x.x is the reserved class c address, where you can have only 253 hosts per subnet


192.168.0.0/16 is not a class b address, the subnet mask 255.255.0.0 belongs to class b, hence your address is subnetted.... why cant you try http://www.subnet-calculator.com/
Reply:Sometimes IP addresses are classful and some times classless depending on how the router is programmed.


When using classfull addressing 192.x.x.x to 223.x.x.x is a range of addresses reserved for class C when using classless it doesn't matter it is just an ip adress range and can be used any way one wishes.