Comments on: Subnetting Shortcuts

By: Jon

Jon — Sat, 03 Mar 2012 21:50:13 +0000

Then take a look at the last octet (since 28 puts us in the last octet range) and divide it by 16. In this case we don’t have to because we can see it is less than 16 but if you are given .189 rather than .7 you would divide 189 by 16 and see that it was over 11.

Where does 11 come from

By: Brian E

Brian E — Sun, 27 Nov 2011 23:34:21 +0000

On Question #1, the second subnet of 192.168.73.46/27 is 32-63, so 192.168.73.62 is a valid host.

By: M. P. Shui

M. P. Shui — Thu, 15 Apr 2010 18:58:37 +0000

I was taught to calculate the number of subnet, hosts, range of valid IPs and the subnet mask of an address from a individual address and mask.

Can you explain how to calculate the total subnet range from a given IP mask, instead of just one?

There has to be a fast way of finding the answers to the above questions, instead of doing each selection individually, especially when taking the Cisco Test

Thank you