Great question. Hang on, cause here goes. Hope this is intelligible.
OK...You expressed your IP initially in bit count fashion (xxx.xxx.xxx.xxx /yy). The '/yy' is just another way to express the subnet mask using the number of bits instead of the binary translation. However, you made an error somewhere here. /24 = 255.255.255.0 However, based on the IP information you later provided, it's clear that your subnet mask is 255.255.255.240, which translates to /28, not /24. Given your IP and subnet mask, all of the other information can be deduced.
I usually think of it this way. The most common subnet mask is 255.255.255.0 or /24. It's easy to see how this give you 256 possible addresses on a single network (xxx.xxx.xxx.0 - .255). However, you must always remember that the first address in a subnet is the network address, and the last address is the broadcast address. This means that you lose 2 addresses, leaving room for 254 hosts.
The easy way to figure out the number of addresses on your network is to take 256, subtract the last number of your subnet mask (assuming the first 3 sets are all 255). In your case, 256 - 240 = 16. This is how many addresses you have in your subnet. Remember that the first and last are reserved though, so you can only have 14 hosts. So it works like this:
192.168.16.0 - network address
192.168.16.1 through .14 - host addresses
192.168.16.15 - broadcast address
The next set of 16 addresses begins with 192.168.16.16 (network address) and runs through .31 (broadcast). You actually have 16 max subnets if you continue this pattern because you can repeat this pattern 16 times before you reach an address of .255 and have to stop. The reason this doesn't jive with your report of 14 max subs is complicated, and involves a bunch of junk that I don't want to get into
You can divide a Class C address into subnets as follows:
Subnet Mask------Bitcount-----# of subnets------hosts/subnet
255.255.255.0--------/24--------------1-------------------254
255.255.255.128----/25--------------2-------------------126
255.255.255.192----/26--------------4-------------------62
255.255.255.224----/27--------------8-------------------30
255.255.255.240----/28--------------16------------------14
255.255.255.248----/29--------------32------------------6
255.255.255.252----/30--------------64------------------2
So you can see that every bit you add doubles the number of subnets available to you. Then you take 256, divide by the number of subnets, and subtract 2 (for the network and broadcast addresses) and that's how you get the number of hosts per subnet.
If this doesn't seem intuitive to you, don't worry. I've been working on this stuff for years, and I still have to consult an IP calculator from time to time. If you want one, I reccomend
IP Subnet Calculator
Hope this helps.
