Welcome to the world of IPv4 subnet mask mastery! In this video, we will uncover some amazing tricks that will help you quickly solve subnetting problems. You will be amazed at how simple it can be once you learn these time-saving techniques.
Contents
Tip #1: Multiply and Jump
Let’s begin by demonstrating our first speed tip using the problem 10.33.85 / 29. As usual, we are provided with a slash 29, which gives us a subnet row of 248 and a group size of 8. Solving for these attributes is a breeze, just by reading the numbers from our cheat sheet.
But here’s where the magic happens. Instead of starting our increments at 0, we can multiply the group size by 10. So, in this case, we start at 80 and continue to increment by 8. We pass our target IP of 85 quickly and effortlessly. The process then continues as usual: the numbers before and after our target IP become the network ID and next network. The next network minus 1 is the broadcast IP, while the first and last hosts are the numbers after the network ID and before the broadcast IP.
Tip #2: Double or Triple
Now, imagine our problem is 10.33.170 / 29. The group size and mask remain the same, so our previous answers are still accurate. However, since we’re in a new subnetwork, the remaining attributes will differ.
We can apply the first speed tip and jump to 80, but getting to 170 from there would be time-consuming. Enter our second part to speed tip #1: we can multiply the group size by 10 and then double or triple it as necessary. In this case, we can go directly to 160, then increment by 8 to 168 and 176. Once we hit 170, we know we’ve passed our target IP. The rest of the process is familiar: fill in the remaining attributes by adding or subtracting 1 as needed.
Tip #3: Find Your Landmarks
Now, let’s tackle 10.33.197 / 30. As always, the cider notation determines our column, which reveals the subnet mask and total number of addresses. Starting at 0 and incrementing by 4 would be time-consuming. Multiplying the group size by 10, as in our first tip, doesn’t help either.
Here’s where tip #3 comes in handy: every group size increment will land on its own subnet mask value or one to the left. In our case, our incremental 4 will eventually land on 252 or 248 or 240. All we need to do is find the closest value to our target IP, which in this case is 192. So, we start at 192 and increment by 4 until we reach 196 and 200. We have now passed our target IP of 197. From here, we fill in the attributes as usual.
Tip #4: Start High, Decrement Smart
Lastly, let’s solve 10.33.117 / 28. The cider notation leads us to the column that reveals the subnet mask and number of IP addresses. Starting at 0 and incrementing by 8 would take up unnecessary time. Multiplying the group size by 10 or starting at 128 doesn’t bring us closer to our target IP.
Here’s where our final speed tip comes into play: start higher than the target IP and decrement by the group size. We know we will eventually land on 128, so we start there and decrement by 8 until we find the block of eight IP addresses that include our target IP. In this case, we find the block at 112. From here, we can solve the remaining attributes, just like we’ve done before.
With these four speed tips in your arsenal, you’ll be able to solve subnetting problems in lightning-quick time. Practice and familiarity with these techniques will have you solving problems in under 60 seconds, possibly even as fast as 10 seconds or less!
So, what are you waiting for? Embrace these time-saving tricks and dive into the world of subnetting mastery. For more tech-related insights, be sure to check out Techal.
You’re now equipped with the secrets to subnetting success. Happy subnetting!
