Professor Messer - Seven Second Subnetting

Subnetting with (almost) zero math. In seven seconds or less!
This is the subnetting procedure I use when taking a certification exam. If you're looking for a way to subnet that is fast, accurate, and simple, this is for you.
I highly recommend that you understand the math behind the subnetting process before watching this video. There's a lot more to know about subnetting than what's in this video!
You may want to reference my other videos that discuss binary math and binary-based subnet calculations:
Binary Math: • Binary Math - CompTIA ...
IPv4 Addresses and Subnetting: • IPv4 Addresses and Sub...

[@Betermin]

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.

[@jeezyii35]

very very true. this is so smooth and straight to the point at the same time very deep but easy to get and learn

[@obinnaonyemaechi4423]

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

[@catman8623]

Im still struggling and feel depressed because I don't understand it. I get the rudiments of subnetting, but all this extra remebering of tables and values is daunting.

[@jdinn32]

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

[@auntiecarol]

Richard Stallman :-)

[@kevinportillo1971]

Not at capes wear heroes :)

[@hellotheir1427]

We all have the potential to be heroes.

[@dustinshort9230]

@@kevinportillo1971 wins the internet

[@kristopherleslie8343]

The man who created the internet *drops mic

[@curtisgalper2825]

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

[@biglawson]

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

[@kakushiafleming8381]

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

[@maa2252]

I completely concur. Amazing.

[@Pluto_ice]

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!!!

[@MalcolmBetruger]

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

[@nathanp.5563]

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!

[@SQLxGuy]

I still don't understand subnetting

[@thealmightychuck2038]

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

[@kuruptzZz]

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

[@j.k.johnson3120]

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.

[@davief6696]

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!

[@nimrod4evR]

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.

[@Brasstoc]

This is pure genius! Thanks Professor!

[@asmacatcat1646]

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!

[@ichibandeath]

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. ✌🏻

[@EMMANUELSOBGA]

He is teaching you the technique and then you'll be able to apply it in seven seconds when you master it.

[@sarahchua2811]

Damn Daniel me too! Struggle in math since elementary haha lol 😂

[@firstname4337]

@@EMMANUELSOBGA it was a joke you stupid shit

[@dylan104]

​@@firstname4337 Why on Earth would anyone like this comment? There's no reason to call him any names. He clarified in the most respectful way possible and had no negative intention. I hope you have had time for some serious introspection in the 11 months since.

[@denmanfite3156]

lol I was thinking this same thing.

[@letterstone32]

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!

[@cmufia1]

Thank you

[@simonpenrose5466]

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

[@lilsista110]

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!!! 💘💘

[@nobody7817]

Someone taught me part of this years ago as I was studying for Net+ from CompTIA. I could NOT remember it, even when going through College. I never did get my CCNA in College; and never could remember the short cuts...though I knew they existed. Now I am being forced to get the CCNA if I want to stay employed... and I am so so so so glad I found this. This brought back everything from College; and from what my friend taught me--and added so much more to it! You are not kidding this makes it far simpler--and much faster than writing everything down! (I have tons of spreadsheets---you would have thought I had figured this out by now--but I was able to look at my spreadsheets (that I created myself) and go "Oh DUH... I did this--and didn't put 2+2 together in my head???"!)

[@SaucySaki]

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

[@johnson554671]

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 KZbin has gone a long way!

[@sarahchua2811]

Elec- 765 can you give some tips before taking the exam? Im struggling with this topic and im planning to take ccna exam. Did you use the same table

[@sarahchua2811]

Zsa zsa thank you so much for the tips reddit is that a website? Thanks again. Your reply will be a very big help for me 👍👍👍

[@fuzylogik]

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 😀

[@marinaivanova5863]

Can you please tell me if on the exam they will ask to write all address out with broadcast, network address for each range (if the question asking to have 4 networks), like on his video 5:00. Or just what professor showed at the end, to be able to determine first, last, network, and broadcast address?

[@baremetalhyperv]

​@@marinaivanova5863 It depends. On mine it was a mix of questions. I did mine last November. You will be able to get easy points by identifying the correct network space by glancing over multi choice options. I would test Messers method by picking an IP address and CIDR notation out of thin air and writing down your answers. Also take 2 minutes to draw up the table of masks with networks and addresses before your exam starts on the virtual whiteboard. I did this and it was super useful reference material. Sorry I know this comment is a year late but if it wont help you it might help others :)

[@funhowtos977]

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. :)

[@mmcyph]

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!

[@lordvader1703]

Did you pass it then? It's been 3 years now

[@williammusgrave8121]

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!!

[@dpreetam]

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.

[@zees9497]

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!!

[@avarissenusert]

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.

[@eddyngoni6681]

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

[@user-bo3yc2ui8s]

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

[@case2329]

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

[@natanquirino5400]

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!

[@tonymania0506]

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

[@jonahallen6636]

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!

[@AlForte13]

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.

[@InsanePainz]

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

[@cyberwave8940]

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.

[@wilIis]

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.

[@sindizel]

I'm scheduled to take this exam from my home. Do you think they'll allow me to bring my pre-made charts into my office for the exam?

[@wilIis]

@@sindizel I took mine at the testing center but I doubt they'll let you use any pre-made notes. You will have the option to use a web-based whiteboard. I'd suggest you practice writing down your whiteboard material to commit it to memory. There is some time while you read the agreement before starting and once you click agree that starts the timer of your exam. Write out your subnet charts during this time.

[@jennifernash4721]

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

[@KrazyKajun602]

Even easier there is online converters and apps for it that give you everything.

[@CryptbloomEnjoyer]

@@KrazyKajun602 Not when you take the CCNA... lol

[@geegonzlz]

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

[@rahulpan1609]

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

[@DerDickePozilist]

Best explanation about subnetting ever! Awesome visuals, too.

[@_tun0]

This mans teaching process is truly a gift from god

[@LaineGaming]

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!

[@phenlism]

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!

[@ruthsan61]

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

[@tigergumby]

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!

[@artscot]

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

[@tearytadpole2651]

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

[@greysonsweval3996]

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

[@tubescott71]

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.

[@alexey2243]

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

[@Devd7]

Did you pass?

[@milostea]

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

[@Natural809]

Thank you so very much for this!!! Plain and simple! I was lost, but I now have a clue! Thank you!!!

[@89JavaBean]

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

[@TreeeSon34]

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 🐏🐏🐏

[@Christian.Knight]

Professor Master. Genius calculation chart, many thanks!!

[@universalponcho]

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. 🙌

[@LordChocolateThunder]

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

[@nghnino]

Dear ProfessorMesser your video is so great and brilliant ! Thank you and more power!

[@WAIT4GOD]

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

[@Smike101]

This man just saved my life. Thank you.

[@charliegrover454]

This is such a great, informational video. Thanks for making this!

[@lionintu]

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

[@chefaaronrussell]

Thank you so much! Very easy to follow and makes total sense. Really appreciate the video!

[@rendelfrancisco2307]

Nice Video for explaining the Subnetting in a simpliest and easiest way! We have the same formula to calculate all the requirements and I finish every subnetting problems in just a seconds. :) Keep it up Sir!

[@adontepatrick7448]

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.

[@mdd1963]

Yes, that's one question you will get right! :)

[@MrMiiman23]

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.

[@drsnooz8112]

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

[@miteshpanchal5080]

Awesome work !!! Subnetting made very easy by Pro. Messer.

[@engelbertventura9949]

Amazing Explanation, easy to follow along to.

[@chrislopez1414]

You are a life saver! Thanks so much for all your help as always

[@jaspalbaath8479]

Excellent explanation!! Thanks Prof Messer for this video.

[@rolandoalmaguer]

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

[@cwsi]

Very simple and enlightening, thank you!

[@abhishekjoshi8063]

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

[@awesomezebra]

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

[@CombatVault]

Excellent video! Helped me study for my interview

[@HowToAl]

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!

[@emiliedionisio9785]

THIS IS AWESOME!!!! Thank you, Professor! Now, I have to go practice.

[@sharankumar7713]

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

[@Threnalin]

Congratulations! Really great video what makes subnetting simple and easy.

[@mananjain8434]

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

[@drgrockster]

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! :)

[@amegabyte7986]

How'd you do?

[@drgrockster]

@@amegabyte7986 I passed! :) and this chart is definitely worth the 5 minutes of time i spent writing it out in the exam

[@amegabyte7986]

@@drgrockster congratulations!! Any tips you'd like to share? Did you write both charts?

[@drgrockster]

@@amegabyte7986 yes both charts, best advice i can give is to really know the material you cannot go back and revisit questions on this exam

[@duncon98]

You really don’t need to write down the charts. It is just involves simple math calculations.

[@bash-ian]

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

[@sariphim]

You’re a lifesaver! Thank you.

[@derekbean]

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

[@durzua07]

This actually really easy. Thank you Professor Messer.

[@lycosa2000]

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!

[@shahwaadkhan675]

Thank you so much prof. please we need more videos like this for cover icnd1 and icnd2.

[@OliverJoshuaJacob]

Thanks for all your help. You are a real hero sir.

[@kingkoopa_]

This is so helpful. Legitimately. Thank you.

[@mahammedsaadsaleh]

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

[@trevoryocky3616]

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

[@acat5819]

Oh my god. Professor Messer, thanks!

[@klentitoska6554]

Simply the best!! Thnx Prof. Messer

[@rjosteris]

What an absolute legend, thank you so much!

[@byrdwakes6315]

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

[@outerzevin1366]

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!

[@thrillhouse4784]

Without the charts? How?