If your are building your own network, or you’re going for the CCNA exam am going to show you in this tutorial how to simply do your IP subnetting and save time during the exam. Although I have simplified such in my previous blog posts.
Now, the aim, for testing you here is know if you will able handle flow of traffics or packets on a network, secondly to know how you can create more networks and host in the case of a scenario if a company or any organization purchase a network address.
Now let us assume that the organization your working for just purchase this network address
18.104.22.168 a class C address with subnet mask 255.255.255.0 and then they want to use this address to address their three different office each having a separate router.
From the scenario above you will notice that the aim here is to create more networks.
So then we are subnetting base on networks. The first thing we will do is to determine our network requirement. Such as how many interface or route do we need to accomplish this task?
From the diagram we need five networks.
So in step1 we will convert the number of our network to binary and determine how many bit it will take us to get to number five.
So we draw our daily chart
128 64 32 16 8 4 2 1
0 0 0 0 0 10 1
so then 5 in binary =00000101
Step2 we are going to reserve Bits in subnet mask and use it to find our increments, so then
Our subnet mask is 255.255.255.0 = 11111111.11111111.11111111.00000000
For us to create more network, we are going to say how many bits did it take us to get to number 5 and then we say 3, if we turn these three bit on now, we will have our new subnet mask. We turned the 3 bit on because our goal here is to create more networks so we have 11111111.11111111.11111111.11100000 = 255.255.255.
Now, what is 3 bit on, as we can see from our chart 128+64+32 =224 and here comes our new subnet mask 255.255.255.224
Step3 which is the final one is to use our increments to find our network ranges.
Note that your increment is the lowest network that you have and that is 32 so here comes our network ranges:
And so on…. coming up on CCNA Exam questions and tips I will give some more piece of information to help speed up your subnetting process.