Professor Messer - Seven Second Subnetting 

I spent 4 hours two days ago, 2 hours the day before that reading a lesson on subnetting and just not getting it. This video obliterated everything I needed to know in the entire lesson in a matter of minutes. Masterful work, Professor.

I felt so depressed because I couldn't understand subnetting, after I watched this video, I felt so good. Now I can deal with any subnetting problem Thank you so Much Prof. Messer

I messaged you four years ago, as I was working on my CCNA. Now, four years later......I am officially a Network Engineer for a world known company. And it is a great pleasure to come back to your education courses that lead me to my career path. I appreciate everything you do and eveyone that I come accross asking me for advice, I always refer them to you education courses, because they are life changing, Thank you.

You probably cannot fathom the number of lives you have changed and are going to change with the sharing of your knowledge. You are a superhero in a class by yourself!!!

I passed N+ a couple of months back, but still needed to comeback to this magnificent video and refresh my knowledge in preparation for my ccna exam

Thank you for this. Calculating networks on Cisco exams has always been my Kryptonite and you have cured me. Thanks again.

1. This is one of the best subnetting vids available online. Use it!!! 2. Passed the Net+ certification exam yesterday with a 751. It is difficult, but it is definitely achievable!

I took graduate courses that gave complicated explanations and methods to solve for subnet networks and hosts. This is by far the best method and ....free. Amazing! Thanks Professor Messer for sharing your wisdom!

Professor Messer’s back must hurt from carrying us ALL. But on a serious note I cannot thank him ENOUGH, he has no idea how much he has saved me from being completely lost during my course. He must be protected at all cost!!

Got every practice test subnetting question right so far using this method. 10/10 would use in exam. ggwp

This is the definition of a genius!! the only simple method ever!!

You call it 7 second subnetting but it's a 21 minute video!!! WTH In all seriousness Thanks so much P. Messer. Your explanations help a guy who really struggled with math in HS. ✌🏻

Is there a bigger hero on the internet? Not many.

Man, you weren't kidding this is really a fast way to Subnet.. Thank you Professor!

Watched this when I was studying for my Net+, now back again for the CCNA.

Very good, but you must review this several times to ensure you understand the process, as the Professor does not waste any words. I re-built his charts and added text as an exercise to recall his logic and his excellent method. Highly recommend!

I have been struggling with subnetting for a while, eventually I got it. But this sir, is something else all together. This is the P.E.D. of certification exam subnetting. I appreciate you.

Thank you SOO much for this breakdown!!! I've been in the medical field for a little over 12-years and I'm JUT stepping out into the world of IT. I have a great teacher who broke everything down but it takes so long to write everything out!!! This is truly a blessing!!! 💘💘

Excellent video. I'm studying CCNA and read the Lammle book. I was confused on Class B & Class A subnetting. Your charts helped me actually understand the addressing and all of a sudden it clicked! Thanks!

Special Thanks To the Messer! Professor Messer. Passed my CCENT ICND1 today 100-105 with flying colors! Network+ training is actually very helpful in prepping for the CCNA. All of your free training on RU-vid has gone a long way!

Have just passed my CompTIA Network+. Thank you professor M, this along with many of your other videos were a great help. Thank you.

I recently passed my Network+ and these charts came in handy big time. I wrote down both charts on my whiteboard before starting the exam, and man it was so nice to be able to quickly answer these questions. I probably had 5 or 6 questions that I answered from the charts.

Great video, I had to watch this a few times to fully appreciate how useful this is, and how I'll be able to save time on test day.

Teaching Subnetting is a skill, one must understand the mastery of teaching first to guide others to the correct path. You have excelled in this. Good work!

This is the best and most straight forward way to easily understand subnetting

You sir, are a gentleman and a scholar. A million thanks!

This mans teaching process is truly a gift from god

Took a few tries to fully understand this way of calculating, but once you understand the rules it is for sure alot quicker. Thanks Professor this has helped alot

Thanks professor messer passed my network + today and subnetting was my leak link until watching this video , your resources for CompTIA exams are simply the best on the web Many thanks 😀

I used Mr Messer's A+ course years ago. It helped me past the test - now I'm trying to get my CCNA, but was having trouble with subnetting. I found this video, and laughed at first. A 20+min video that says seven second subnetting in it's title! Then I saw all his charts and I was like how is this going to help and how am i going to memorize this??? After practicing with the charts and how easy it is to remember them - I was like WOW! this is really easy and helpful! I was very skeptical in the beginning, but Mr Messer has come thru again!! Good job, Great video!!

Thank you Professor Messer, came back to this for a refresher, best subnetting tutorial and the charts are a gem!

I know I've commented on this before but I have my test coming up and rewatching this a few times really helps me understand the logic. Still going to practice the hell out of it. Thanks.

This is pure genius! Thanks Professor!

I will probably cherish this video for the rest of my life. If there is an award for best educational video i would nominate this one 1st place.

Excellent video! I have always had trouble with subnetting, this in formation was great. I am currently in a routing class, and this video just made my class a lot easier. :)

Wow! Thank you. I was close, but after using your method I no longer even need the charts. Locked in now. TY.

Holy moly I was pulling my hair out trying to understand this. You really broke it down and explained perfectly. I was making mistakes along the way, but once I got to the last problem I was able to do it myself and got it right! Thank you so so much, Prof!

I'm on my journey to become CCNA certified, but although i understand the math behind subnetting the math itself takes way to long for me this has helped a ton!

I started looking at this topic last night and found your video. I took the time to go back and look at the charts and learn how each number related to the others and after about 12 hours of practice I can do these without the chart! Thanks for this video! It really helped me grasp this stuff!

Thank you so much, I've been struggling with this for days i finally get the answers i want!!. Now i wont spend more than 5 minutes on subnetting questions

Thank you, Mr. Messer, I purchased your ICND1 study guide and pass the Cisco Exam-ICND1.

Best explanation ever! Taking my CCNA tomorrow and for sure will draw this before even timer begins. Thanks!

Wow! Absolutely amazing video. You've got to patent this! All jokes aside, I was absolutely terrified when it came to subnetting anything lower than a /24. Thanks to your video, I can subnet any CIDR addressing scheme within seconds.

Going to sit my CCNA in a few days time and I was stressing about how to divide 16384 by 256 in a hurry. this video has helped in a huge way, thank you Professor Messer! :)

This is the only video I watched that explained a question that I had. If you have a /26, for example... WHY are there 4 networks? I had a suspicion that the 2 extra subnet bits were being manipulated to equate to 0 - 3, but not a single video out there explained that. Either they tried to make it too easy by using a table, or just glazed over that point and said that the 2 extra bits that were snagged out of the last octet gave you 4 networks without explaining why that is. So thank you for answering a question I spent all too long trying to figure out. I even took a CompTIA Net+ class through work and it wasn't explained. It's such a simple answer. Without answering that question, it didn't make sense how different host addresses landed you in different networks. Too many videos act like those bits are always on and that by choosing a /26, those 2 extra bits are static. Thank you very much for this video!

Professor Messer you're a FREAKIN GENUIS! Doing subnet mask was the only part that I was struggling with with understanding. This video is AMAZING! Now that I got this in the bag time to start doing practice exams! Wish me luck!

This was great! I've been struggling with this topic for weeks and this literally just made everything click in and able to calculate easily now. Thanks!!

I’m currently in training for 25 Bravo (IT Specialist) for the Army and Professor Messer has helped me so much over the passed couple of days while I get ready for a networking test!

QUESTION: It was unclear as to when you created the charts. I assume we are not permitted to bring these charts into the exam; rather, we must create them DURING the exam. Am I correct in my assumption? PERSONAL OBSERVATIONS: I've practiced and timed myself creating these charts - flawlessly; and, yes, counting by powers of two followed by counting in increments of fours without mucking it up is mental gymnastics and requires practice to execute quickly and accurately! If you want to use these charts, do yourself a favor and PRACTICE making them! Use a mechanical pencil. Standard graph paper is too small; so, I created custom graph paper in MS Excel with just enough grids to accommodate the CIDR chart and two blocks of 128 addresses so that they fit on a single 8.5" x 11" sheet of paper in landscape format. Each grid is 33 pixels high x 37 pixels wide. Cell border color is set to a light shade of gray or other color you like. To get the grid to print out, populate each cell with any alpha or numeric character and format it as white text, then print out several two-sided sheets for practice. My best time in creating the charts is 6 minutes, 11 seconds. (Windows ships with a stopwatch, did you know that? It's in the alarm app.) Minimally, for me, increments of four must be written at the bottom row; and, the vertical boundary lines for 8, 16, 32 and 64 are must-haves. The first boundary line of the first block of 128 addresses is zero; and the first boundary line of of the second block of 128 addresses is 128. In any case, I spent a few days playing with these charts and double-checking my results using binary math. I like the system. Identifying the Subnet mask; Net ID; and Broadcast, first, and last IP addresses is fast. SUGGESTIONS: Use a 0.5 mm mechanical pencil - the fine lines this pencil draws permits writing smaller numbers. Have an eraser; because, I can almost guarantee you'll place boundary lines in the wrong place or goof-up on counting by fours within the first and last five iterations...at least once. Endeavor to get it perfect start-to-finish without erasing. :-) Good luck. Thank you, Professor Messer, for creating and sharing this system.

Wow that chart is amazing! it helps with subnetting understanding, but also allows you to understand subnetting and not be reliable on it. THank you!

Is there time to write out these charts during the exam? My concern is that it will take a while to get it all written down and you'll lose at least a couple of minutes of time, which can be a problem particularly if there are 90 questions and you only have about a minute per question. Any advice? I was thinking of just memorizing the charts to the point where I can do these problems in my head.

Can't thank you enough! I will sit for the booth in about 2-3 weeks and I'm sure this alone will help boost my overall score.

WOW this is totally BREATH TAKING! - Professor Messer you have an excellent handle on subnetting thank you for passing it down to all of us.

Professor, it's been said here many times, but FOR REAL. You can't believe how many people dread subnetting. The fact that you're providing this method for free is just... Wow. You are definitely the 🐏🐏🐏

OMG...I think I finally got "it" after the examples....amazing....those charts are DO or Die! Thank you!!!!

Had to rewatch the video a few times but it finally clicked. Thanks Prof. Messer!!

I've always had trouble understanding how to subnet but this breaks it down so much easier. Thank you for this.

Heres a tip if you struggle with the big chart. Do the 4s first. Write the line all the way to 96. Make another line under your 0, and start over (but from 100). The numbers repeat. Do this again for 200 Another tip is that since every step doubles, the next number in the next line will be the same number as the last line but skipping one. EX- 16 - 0 16 32 48 64 EX - 32 - 0 32 64 See how its the same if you just skip a number from each step? Draw the 16 chart, and then just skip 16 and 48

Professor Messer. Einstein doesn't have anything on you. You have blown my brain. Thank you a thousand times a thousands. I am definitely going to buy some of your educational products. That is a promise. I have been looking at this subnet material like a deer in headlights until you came along.

Thank You Professor Messer , There is no Subnetting solutions as fast as this one Amazing Chart

Just passed my ICND1 (just under the Feb 24 wire) thanks to you Mr. Messer.

Honestly THE best explanation for quick subnetting I’ve ever seen!!!!! Awesome job Professor!!

after spending a lot of time to master subnetting, this video alone gives you everting you want

Professor you are such a great person, I understood it very well now, Thanks a lot........

I've never seen this method before. I always drew out a chart for my cert exams, just not these charts. This is really fast.

Oh my God. If I knew this video was a thing while I was in my networking class. Subnetting would've been a cake walk

Excellent method. After a few exercises it became quite easier to get the answers. Thank you.

You have made my life sooooo much easier. I can not say thank you enough Professor!!!

This video pretty much got me over the hump for subnetting!

Just passed N+, Thanks Professor Messer, this technique saved me during the exam!

Dude I have spent weeks trying to understand this stuff. I understand the binary math and stuff like that. After this. It has all fallen in to place. Thank you very much. 🙌

Just adding to the masses thank you so much for all you do taught me so much so quickly

Thank you so much! This makes it so much easier to calculate!

Well thats awesme method to solve subnets problem. You were genious professor. Thankyou so much for this.

This has made my understanding so much easier... Thanks...

This man just saved my life. Thank you.

Dang bro. This is great! Thank you!

Wow I totally loved this my friend. Youre amazing for this.

This is the best subnetting video that I have seen. Cheers!

Can we all allow Prof Messer to solve economic and political issues in the WH like subnetting math! Yo my brain cells are highly QUANTIZED, Thank you 2^1000000

This is so good it hurts, so smart it's scary. Thank you for sharing your genius!

Will I be able to write these tables before my exam start or will I have to wait until right when it begins? CCNA. Such an awesome video, thank you so much for sharing!

Excellent video! Helped me study for my interview

Professor Master. Genius calculation chart, many thanks!!

Thank you much ! Your subnetting video made a lot easier to solve subnet mask. Appreciate your help.

Taking Exam on the 19th Feb 2018 and I will be using your method. Thank you for sharing.

About to take my Net+ and my brain has been made into mush by all of the routing protocols that I had to remember. Somehow my brain was like, "welp, we don't need subnetting, lets go throw this away" and i've been stuck in a week-long brain fart over this. Thank you for sharing, i'm trying to quiz myself on subnetting random IP addresses into smaller subnets.

this video is mind blowing Thank you so much sir

Phenomenal, I truly enjoyed this. Thank you for taking the time to do this.

just you made it super easy, thank you

Wow! Just Wow! You're awesome Professor! Subnetting is easy-peasy from now on!

By far the best way to do subnetting.

This is extremely helpful! Thanks professor Messer!

Great video, and wonderful explanation. These charts would have helped during my exams, definitely would have saved a lot of number crunching. Now I know what I will use going forward, thank you so much!

Professor Messer strikes again.. Thanks for the content! Quick question, what's the easiest way to find the number of usable IPs?? Thanks again!!

Legit Genius and the easiest way to subnet! Great job! AND THANKS SO MUCH!

Thank you for providing such a wonderful explanation of this. I viewed plenty of tutorials and "calculator" videos and mostly understood these concepts. This video finally gave me the "Aha!" moment. Thank you so much!

This is GOLD!!!! I wish my professor explained it like this!!

This is incredibly helpful!!! Thank you so much!!

Its very good explanation, I finally starting to understand but the address chart will take ages to write out