One of the most handy utilities I’ve used for a long time is ipcalc. It basically gives you all sorts of information on IP addressing, subnets, etc. The output looks like this:
It seems the RedHat engineers have a bit of their own mind and so they come up with a different version which doesn’t resemble anything at all on the above picture but looks like this but uses the same name:
So in case you still want the above do a “yum install ipcalculator” and add an ipc alias for abbreviation in your .bashrc file.
ipc x.x.x.x/xx give then the above shown output.