Subnetting in the /17 - /24 range - Subnetting Mastery - Part 6 of 7

[@PracticalNetworking]

All the videos in the series and the problem generator is available here: SubnetIPv4.com Want to learn the Fundamentals of Networking? www.practicalnetworking.net/index/networking-fundamentals-how-data-moves-through-the-internet/ Studying for the CCNA? Here are free resources to help you learn: www.practicalnetworking.net/index/ccna/ If you enjoyed this content, don't forget to show your support by liking, subscribing, and sharing this content amongst your peers. That would really help me out. Thank you!

[@jeffgowell3105]

MUCH appreciated as I have literally spent thousands on my Network+ and A+ courses !!!

[@cto1011]

These videos are so great. You can go back after you forgot this and it all comes right back. The best subnetting explanation out there.

[@Modassirhassan10]

You have no idea sir, what have you done by illustrating Subnetting in so easy language! I have been trying to understand it for weeks, searched so many videos on KZbin but you're the only one who has cleared my doubts! Thank you so much!

[@PracticalNetworking]

This post made me smile. I'm so happy you found understanding with these videos. =). Please tell your peers and collogues about this resource. =)

[@Modassirhassan10]

@@PracticalNetworking I have a question, how to calculate the subnet of 1.1.1.1/1. Can you or somebody please explain it? It would be really helpful for me!

[@emileakuamoah7289]

This guy here is genius. So far this's the best series of subnetting i have seen so far.

[@chriszale2843]

Life Changing .....I am a noob IT guy, and starting with Network + . The videos, along with the practice site have made subnetting completely "click" for me! Thank you!

[@PracticalNetworking]

Awesome Chris, I'm so happy to hear these helped you =). Good luck with your Net +

[@TriviumDFTS]

I've been on and off studying for my CCNA for almost a year now. I've recently had time to get really serious about it due to COVID. These videos have helped TREMENDOUSLY. This series is a must have for subnetting. Thank you!

[@PracticalNetworking]

Hello =) So glad you enjoyed the content. Thank you for the kind words.

[@theaajourney9872]

have you taken the CCNA yet?

[@jimboelterdotcomm9153]

So many training materials just discuss how to handle the 4th octet, and leave you floundering when you need to solve problems for the higher ones (I know, the principle is still there, but it's a little slippery for those of us coming to subnetting in later years). Appreciate your taking the time and energy to deal with 3rd octet problems.

[@PracticalNetworking]

Glad you enjoyed this series, Jim =). Could you do me a favor? Do you mind sharing this video on Linked In, Reddit, Facebook, or any other social media you use? As an independent creator, that would be an _enormous_ help, and I would appreciate it _greatly_ .

[@lukemalby793]

Legend! These videos are the best resources to learn subnetting by far. I have literally tried just about every method and found this one the easiest, quickest and with the least chances to make a mistake. Appreciate your work!

[@PracticalNetworking]

Thank you for the kind words =). I'm glad you enjoyed them.

[@bpet7138]

Brother this is a game changer. Failed my first CCNA attempt because of some nasty subnet questions. THANK YOU

[@engralikhan333]

Well beyond the approach of any professor or instructor. You are doing a brilliant job. Well done

[@PracticalNetworking]

Thanks for the kind words, Muhammad. I'm glad you enjoyed this series!

[@toastymcgee9788]

You...are amazing. How is it that everyone has a different method of understanding and explaining this process? This is easily the most straight forward and easy to understand which is really what matters here.

[@PracticalNetworking]

I agree with you =). I do think this is the best way to understand, do, and teach subnetting =). Thanks for the kind words.

[@jameselrick6698]

I literally can't thank you enough for your video's! It's been rattling in my head on how to do sub-netting for months now, but thanks to you and your websites! I've been able to do quick pulls on sub-netting in 30 seconds! That's a fantastic improvement, and I for one can't wait to go take my net+ now! Thank you again, and you got yourself a new subscriber.

[@PracticalNetworking]

That's awesome, James! Glad you're now a subnet master =). Thank you for your support! Could you do me a favor? Do you mind sharing this video on Linked In, Reddit, Facebook, or any other social media you use? As an independent creator, that would be an _enormous_ help, and I would appreciate it _greatly_ .

[@jameselrick6698]

@@PracticalNetworking Very late reply, but I've already shared it with friends. They've been starting networking careers, and having your vids made it very easy to pick up. I'll be recommending you, no worries 👍

[@PracticalNetworking]

@@jameselrick6698 Thank you James. Much appreciated !

[@chickenonbeachball9057]

for 2 weeks I tried to get m head around subnetting, your video has done it in under an hour. Thank you.

[@PracticalNetworking]

Wish you had found these two weeks ago! =). Glad you got it now. If you can, sharing these videos with others is the best way to return the favor. Either way, you're very welcome.

[@jeffgowell3105]

These video's convinced me I can do subnetting at 60 years old with NO IT experience !!! I'm going to check and see if there are more videos like this on DHCP and DNS which is kicking my ass LOL

[@israelflores9001]

This....This is so STUPID EASY!!!!! I can not believe how much I have stressed over subnetting for my CCNA. A very BIG THANK YOU! THANK YOU! THANK YOU!

[@PracticalNetworking]

Cheers Israel! So happy it all makes sense for you now =) Could you do me a favor? Do you mind sharing this video on Linked In, Reddit, Twitter, Facebook, or any other social media you use? As an independent creator, that would be an _enormous_ help, and I would appreciate it _greatly_ .

[@8bit-BlackCascadia]

Absolutely the best way of learning to subnet. You rock. Huge Thank You. I have learned to subnet in a day.

[@PracticalNetworking]

Wohooo! Congratulations!

[@PracticalNetworking]

Who knew subnetting in the 3rd octet would be just as easy?

[@catlover1157]

Why Subtract 32 with 21 for the 10.4.235.19/21 to calculate the # of IP addresses ?

[@RohIt_bhopali]

@@catlover1157Hello to you. It's been done because now as you can see we have moved to the third octet and in here we can't simply go by the method of group size since using the numbers like before would create confusion as to what can be the total no. of IP addresses. For example, 10.3.3.147 /27 has total IPs = group size, i.e., 32 likewise, if 10.4.77.188 /19 also have total IPs = group size then its wrong, since going by CIDR notation now Host bits left are (IPv4 is 32 bits long) 32 total bits-19 network bits = 13, thus total IPs = 2^(32-19) used. Now in the 1st ex, total IPs = group size make sense because Host bits left are CIDR - 27 = 5, so ans is 2^5. This is implicit. Hope you understood!

[@dinorossi6611]

O yah, sure. All we need is a plucked hair of a sleeping yeti to complete this soup.

[@TedTheAtheist]

There's an easier way. Just do 256 x the amount of available IPs to get your answer, since it's the 3rd octet. If it was the second octet you'd just do 32768 x the amount of available IPs for that octet.

[@channelz1xwebr]

@@TedTheAtheist Thank you!

[@ArchiveCurator]

want to say thank you for this, I've learned so much from these mastery videos.

[@ryahya94]

thank you this is the 5th channel i found that worked for me the best!

[@kalaiarasanj4595]

First of all, thank you so much for these videos, it will help me to do as quick as possible of subnetting and better understanding.

[@libaaxalee]

Without a doubt to me this is the easiest way to subnetting, appreciate your help.

[@PracticalNetworking]

Thanks for saying that. I'm you liked this method!

[@sabrinasegura5771]

First… THANK YOU. I was taking a class and literally stopped and rethought my entire career change based on how subnetting was taught..until now! What I don’t understand why on 3 octet broadcast ends in .255 and last host on .254. And then first host is .1. Ya lost me there 😢. Thanks again! I have already sent the series to a ton of friends!

[@Cloud_with_lois]

did you finally get an answer to this?

[@AnnCherryCervitillo]

any answer to this?

[@rduhoo]

These videos are great! I was struggling with subnetting and was really stressed about it. Now I got it. Thank you!

[@PracticalNetworking]

So glad these videos have given you less stress =)

[@RohIt_bhopali]

Its been an awesome series you made Ed! I have been in love with your work and how you teach! Please continue making such amazing visual learning videos.

[@PracticalNetworking]

Thanks for the kind words, Shubhendu! Glad you enjoyed the content!

[@muhammedmokrane1440]

YOU NEED MORE THAN LIKE, thank you for amazing work

[@PracticalNetworking]

Thank you for the kind words, glad you enjoyed the series =)

[@kushoza43d24]

Best Video on Subnetting on KZbin!!!!

[@karenfitzgerald1910]

Where does the .255 come from in the last host address at 3:13?

[@susmitamazumder8390]

Your videos are the best. Please continue the network fundamentals videos. Are you convinced by all of our good words!!!!!! 😊

[@PracticalNetworking]

It certainly is nice to hear how people have enjoyed the content. =)

[@abdihalim7788]

This videos have helped me tremendously a lot am preparing for my Network+ exam and I have crunch the information of subnetting for 2 days by watching this videos , I appreciate a lot your concern sir , you really helped people. I would like to know if you have PBQs you performed on videos . 🙏 Thanks a lot once again

[@quex213]

I hated maths in school years, now numbers are essential in my (hopefully) future job. How life changes lol ! This was sooo easy, anyone can learn this ! Cheers

[@TheOnlineMarket]

THIS IS HOW YOU TEACH!! Thanks man

[@PracticalNetworking]

Glad you enjoyed it =)

[@jdgtnight]

This series saves time, very satisfiying ;)

[@meganeox]

This was soooooooooooo helpful. I understood how to do it for the fourth octet but I couldn’t figure out the third. Thank you so much!!

[@PracticalNetworking]

That's awesome, Meganeox! Glad you can Subnet in the 3rd Octet. Hopefully the 1st and 2nd Octet as well after the next video =)

[@SouperMaruchan]

Thanks bro. I was really struggling with subnetting. This series has helped a lot

[@PracticalNetworking]

Awesome! So glad you've now figured it out =)

[@BestLine-h1v]

Thank you Sir I really enjoy your videos God bless you with long life as well.

[@HichamDgadeg]

thank you so much for these series

[@malickcamara5953]

Incredibly gifted!

[@ahmedal-aqel]

Thanks alot for what you do, really awsome guy, great way of teaching 🌹. to know that i told all my glassmate watching this playlist and all videos on your channel..😊😅 greatings from yemen ❤

[@willgreat8384]

Made the third octet look easy , I’m glad they are not gonna ask me to do any 2^n notation without a calculator I would fail .

[@PracticalNetworking]

Aren't we all! =)

[@amitroy-kh1wn]

Greate learning ever. Just waiting for these video series

[@Anthony-MO]

You sir are a legend, thank you.

[@connief2679]

Fantastic!! You are a magician!!

[@PracticalNetworking]

Thank you! Cheers!

[@HichamDgadeg]

in 2^(32-CIDR) why do we subtract the CIDR from 32 ? where that 32 come from ? and thank you

[@Shavontay66]

Y'all wish me luck on finals omfg

[@thomasadkins5009]

for the number of ip addresses, i just multiply the group size by 256 :) just simpler math

[@PracticalNetworking]

Yup! That totally works for 3rd Octet. For 2nd Octet, you'd multiply by 256 twice (256 * 256 * group size). For 1st Octet, you'd do it 3 times: (256 * 256 * 256 * group size). But that starts to get difficult, so I opted not to include that trick to finding # of addresses. But it does absolutely work =)

[@ericalvaradoochoa3090]

Hey i am a little confused on /24. Can you explain to me how you would subnet a slash /24 if it has a Group size of one ?

[@PracticalNetworking]

The group size of 1 is in the 3rd Octet. So if I were listing all the /24's starting from 10.0.0.0/8, it would be: 10.0.0.0/24 10.0.1.0/24 10.0.2.0/24 10.0.3.0/24 ... 10.0.254.0/24 10.0.255.0/24 10.1.0.0/24 10.1.1.0/24 10.1.2.0/24 10.1.3.0/24 ... HTH

[@gavishtaliyanage481]

These videos are super . Explained neatly in a way we can remember subnetting. Thank you. Can you please do some videos on supernetting.

[@PracticalNetworking]

Glad you enjoyed the videos =). I've made a note about Supernetting. Thanks for the suggestion.

[@MusaTheGamer]

Indeed you have aided me in being a subnetting master

[@PracticalNetworking]

Woohooo! Congratulations =)

[@metoshinakamoto6658]

Great video, an easier way to determine # of IPs is: group size * 256

[@PracticalNetworking]

That works for 3rd Octet. For 2nd Octet you'd have to do Group Size * 256 * 256... and 1st Octet would be Group Size * 256 * 256 * 256. Since that gets difficult to do I chose to include the 2^N method for # of IPs for 3rd Octet. But it does work =)

[@jbserious]

Insane...thank you!

[@ajaxSAF]

Huge help, thanks so much

[@PracticalNetworking]

You're very welcome

[@holhorse3080]

Thanks for this course, but I've got a question: would it still be appropriate to call the 1st row of the cheat sheet to be the "group size", since we're now working with the 3rd octet?

[@gustavod.4795]

this works really well thank you

[@axiseast8409]

God bless you !

[@PracticalNetworking]

It was fun seeing your comments on the videos progress to this. Happy you enjoyed the content!

[@mundoin5583]

Great explanations and very very helpful. My question is how do we "reverse engineer" this method if all we have is a network ID ?

[@PracticalNetworking]

Good question. Remember that a network ID by itself does not identify a particular subnet. I talk about that in the first video. Hence, you really can't calculate anything with only a network ID. Certain (rather legacy) protocols will infer a subnet mask based upon the IP address's class... But that behavior is rarely accurate or effective for the modern day. More details here: www.practicalnetworking.net/stand-alone/classful-cidr-flsm-vlsm/

[@ObitoUchiha-ms6xt]

How about /24 which increment is 1 ? We increase until

[@PracticalNetworking]

Yes, exactly! ;) In most cases, you'll only need to increase the 3rd octet once. That is what makes "subnetting" with /24's so easy. (and /16s, and /8s, for that matter)

[@original-bug]

at last question you change .4 to .5 you ca not change the network bit !! change only on 3rd octet and 4th octet !!!! explain ?

[@PracticalNetworking]

Every time you identify the "next network", you are changing the network bit. Since you are identifying *another* network, you in fact *must* change the network bit. If you didn't, then you would simply be displaying IP addresses in the same network. You did the math correctly in your other answer though =)

[@ah76013]

Good video

[@stokedradar]

This may sound slow but my question would be how would we determine total possible number of networks? We can determine total possible number of hosts and useable hosts. Im not sure how to find total networks.

[@PracticalNetworking]

That is answered in the FLSM/VLSM appendix videos to this series: kzbin.info/www/bejne/fGGYpHeCjbR5npo kzbin.info/www/bejne/l56uqpmYnJp6aLM

[@Sesu22]

i've got a question. say i had a /23 network with IP address of 10.4.120.100... what would my network ID be? 10.4.120.0 or 10.4.120.100?

[@Douglas_Gillette]

1. Convert the third octet of the IP address to binary. This will give you a binary representation of that octet. 2. Convert the third octet of the subnet mask to binary. This is necessary for the logical AND operation. 3. Perform a logical AND operation between the third octet of the IP address and the third octet of the subnet mask. This will isolate the network portion of the third octet by comparing the binary values of the IP address and the subnet mask. 4. Convert the resulting binary value back to decimal. This will give you the network address for the third octet. 5. Combine with the other octets as necessary. The remaining octets may or may not be affected by the subnet mask, depending on its specific value.

[@PracticalNetworking]

Everyone is different, of course, but personally I prefer avoiding binary when doing subnetting if I can =)

[@Pavel-my4pr]

great video

[@PracticalNetworking]

Thanks again, Pavel =)

[@Statalyzer]

Doesn't 256*[group size] also work for total # of IP addresses in the Third Octet?

[@PracticalNetworking]

Yup! And 256*256*[group size] for 2nd Octet. And 256*256*256*[group size] for 1st Octet. There are other ways that work as well (2^N, for example, discussed in Video 8).

[@calebw5290]

I'm not sure why I can't grasp how you get the 4th octet to go from .255 to .0 and then to .1 in example 2.

[@dirkdeboer6569]

this made it so easy!

[@TheFrancisChowdhury]

Just wondering Using this cheat sheet , is it possible to calculate how manu subnets do we have? For example, Class A 60.0.0.0/8 If we subnet this into /19 networks, how many subnets do we have?

[@PracticalNetworking]

Absolutely! In fact, you don't even need the cheat sheet for that. I discuss how to solve those problems in the FLSM video of this series: kzbin.info/www/bejne/fGGYpHeCjbR5npo

[@TheFrancisChowdhury]

@@PracticalNetworking Thanks a lot

[@xkorbekx]

hi using your method to find last valid host on the network 172.17.128.0/19 I got 172.17.255.254 as last host but my answer is wrong according to subnetting.net the correct answer 172.17.159.254???

[@PracticalNetworking]

The group size for a /19 is 32, which will be the increment in the 3rd Octet. From a starting point of 172.17.128.0, the next network would be 172.17.160.0 -- which would make the broadcast and last host 172.17.159.255 and 172.17.159.254. It seems you had a mistake in your addition and ended up at 172.18.0.0 as your next network (and therefore 172.17.255.255 and .254 as your broadcast and last host). So, just a simple addition mistake =)

[@xkorbekx]

@@PracticalNetworking yea i think i been studying too hard 128 + 32 is indeed 160 lol. i forgot to continue adding the group size. I added 128 + 128 to get 256 then added +1 to 2nd octet. thank you for demystifying this.

[@dakarishelby]

Where does the number 32 come from?

[@PracticalNetworking]

In what sense? 32 bits in an IP Address? That was chosen arbitrarily back in the 70s (when we thought 4 billion~ addresses would be enough).

[@ahmadba1928]

Danke 👍

[@PracticalNetworking]

You're welcome!

[@akilasundaresh8887]

How to calculate number of subnets using this method?

[@PracticalNetworking]

I unpack that in video 8: kzbin.info/aero/PLIFyRwBY_4bQUE4IB5c4VPRyDoLgOdExE

[@Kohyongkeng]

my math is not that good briefly explain how come we can use 32-19 to obtain the #IP address? thanks

[@shaikibrahim9435]

How about Class C and B Subnetting? The same formula works, else does have something different.

[@Linuxenthusiast]

How do we find the number of subnets?

[@PracticalNetworking]

That's discussed in the FLSM video (Video 8).

[@MikeD-dp4vk]

Why is the first network ID 10.4.64.0 and not 10.4.0.0 nor 10.4.32.0?

[@PracticalNetworking]

A /19 falls in the 3rd octet, so the "target IP" we are aiming for is the third octet -- 77 in the example. So the NetID and Next Network would fall on either side of 77, giving you 10.4.64.0 and 10.4.96.0.

[@MikeD-dp4vk]

@@PracticalNetworking thank you!

[@talalazzam4760]

does this work for all classes A, B, and C?

[@devesh09]

Can someone name this song 0:10

[@admin_e]

👍👍👍

[@ramdogproductions]

Love these!! Great graphics and voice over ;-) I noticed you don't subtract two IP addresses for the total # of IP addresses. Love to hear your thoughts. I'm new to networking so this is very helpful as I study for the CCNA. Cheers

[@PracticalNetworking]

Glad you're enjoying this. The -2 only needs to happen if someone is asking for the total *usable* addresses. The *total* addresses is always as the video mentioned (without -2). The -2 itself comes from the Network ID and Broadcast IP being unusable by Hosts on a Subnet. I unpack that in the first video of the series.

[@ramdogproductions]

@@PracticalNetworking Agree. Thnx for the fast reply!!

[@mikecopeland7358]

This is brilliant Sir. I am uncertain about why in the example for IP 10.4.235.99/21 you subtracted 21 from 32 for # of IPs when we were working with a group size of 8 in the 3rd octet. Why wouldn't it be 21-8 for 2^13-2 = 8190 usable IPs? Thank you so much!

[@mikecopeland7358]

Hmm, is it because we used the time hack of grouping by 32 instead of 8 to begin sub-netting down?

[@PracticalNetworking]

Glad you liked it. For # of IPs, we always subtract from 32 (the total number of Bits in an IPv4 address). You can validate this with the fourth octet. A /29 has a Group Size of 8, which means 8 total IP addresses. You can also get this by doing 32-29 = 3, and 2^3 = 8. So either way you get the same answer.

[@mikecopeland7358]

@@PracticalNetworking Brilliant! Thank you again for posting on this topic and for always answering questions so quickly.

[@pnuema1618]

GOLD!

[@DanieleGambera]

First of, congratulations for the great videos series. I am facing an issue, however, when subnetting /16 and /24 as it seems the rules explained in videos do not apply. It might also be I have missed the detail on how to deal with these cases, so, please, forgive me, just in case and point me out to the exact video where I can view the explanation. Let's go by example. 145.104.128.127/24 According to the cheat sheet, the group size is 1, so, I would expect the Network ID to be 145.104.127.0 and the Next Network to be 145.104.128.0. Instead, from the practice page the Network ID is 145.104.128.0 and the Next Network is 145.104.129.0. Basically, the Network ID is the same of the IP given for the exercise after setting to 0 the last octet, but according to the algorithm, I should add 1 (the group size) to the 2nd octet starting from 0, until I PASS the given IP: in this way I would find the Next Network (which should be 145.104.128.0 in the example above). And the IP before it in the count (145.104.127.0) should be the Network ID. This happens to all the /24 class IPs that I encounter in the practice page. In the same way, this happens for all the /16 cases (of course, after zeroing the last 2 octets of the given IP). I have not got chance to encounter /8 cases, but I guess it's gonna be the same. Now, I am pretty sure I am wrong and the above is the right way to do the exercise, would you be so kind to explain what I am doing wrong? Thank you PS: I just checked also a /8 case an the same happens. And as further test I tried also /32 and the same applied.

[@PracticalNetworking]

Hrmm, I think you are off by one. So given your original example: 145.104.128.127 /24 Target IP 145.104. 1 145.104. 2 145.104. 3 145.104. ... 145.104. 126 145.104. 127 145.104. 128

[@DanieleGambera]

@@PracticalNetworking thank you for your reply. Reading what you said, I have to admit I totally messed up, maybe because I am too new to this. I also called the 3rd octet "2nd octet" by mistake. You explanation totally makes sense to me: I have just to overcome the value in the relevant octet for the given IP to obtain the Next Network ID. And the previous one in the count will be the Network ID instead. Since Group Size is 1, it makes absolutely sense that the value in the relevant octet of the given IP is the same of the Network ID. Thanks a lot!

[@PracticalNetworking]

@@DanieleGambera You're welcome. Glad it makes sense now =).

[@marksummers463]

Oh yeah!

[@udayjkc]

what is the number of possible networks in the first example ?

[@PracticalNetworking]

The first network can be split into any number of networks of any number of sizes. Without knowing the size of networks you want, that question can not be answered. It's like saying "how many pieces in a cake"... it can be divided into four slices, or eight slices, or whatever other number of slices. Now, if you're getting that question from an instructor or homework assignment, it is likely assuming a network size based upon the IP addresses' "class". However, Classful networking is a legacy concept. I wrote about it here: www.practicalnetworking.net/stand-alone/classful-cidr-flsm-vlsm/

[@Cameronbic]

I feel like the calculations for number of addresses are less complex if you just say the Group Size times 256.

[@PracticalNetworking]

Totally! I mention that in live classes. But for this series I skipped that strategy because it becomes more complex in the 2nd Octet (Group Size * 256 * 256) and 1st Octet (Group Size * 256 * 256 * 256). Either way, there are probably many ways to get the right answer. This was just one I picked to include in this series. But good call, Cam =).

[@prestoneagle2718]

WATCH THIS BEFORE YOUR TEST!!! I just watched the other ones and they gave me a /16 or /19 and I missed it because I was confused!!!

[@luscious5150]

Hi-confused on this video. Why wouldn’t the first host not be 10.4.233.0? Why wouldn’t the broadcast be 10.4.239.0? Why wouldn’t the last host not be 10.4.238.0?

[@PracticalNetworking]

Because the +1 and -1 calculations are always done on the 4th octet, regardless of where the "relevant" octet of the problem itself. The IP 10.4.232.0 is the Network ID, and to do +1, you are looking for the IP address *immediately* next, which would be 10.4.232.1. The Next-Network is 10.4.240.0, and to do -1, you are looking for the IP address *immediately* before, which would be 10.4.239.255. Consider it like counting. If I told you to count in sets of 100, you would say "100, 200, 300, 400, 500, etc...". If I told you to give me +1 on 300 you would give me 301. If I asked for -1 on 400, you would give me 399. Hope this helps.

[@jaelski1217]

How could I apply these techniques, when given an IP then given a required number of hosts or subnets? Never mind, I just watched the vlsm and flsm videos. Really awesome!

[@PracticalNetworking]

=)

[@original-bug]

last answer will we 10.4.192.0 NID 10.4.192.1 valid host 10.4.255.254 valid host 10.4.255.255 BID

[@PracticalNetworking]

Yup!

[@seca_999]

why doesnt university teachers teach like this ???? omg

[@Fredjoe5]

People keep saying subnetting is easy. It's not.

[@SruthiSNair]

[@TedTheAtheist]

Hey there beautiful Indian lady

[@fmartinez004]

slow down, you talk to fast

[@PracticalNetworking]

YT has the ability to speed up or slow down the playback speed.

[@ashifalohanchowdhury9475]

why u talk so fast?? are in the toilet??running outta water there?? or you are in the battlefield??

[@Modassirhassan10]

Hey, that's very rude of you! Have some respect. He's teaching us Subnetting in the simplest way possible for free and if you don't like the speed of his talking, then don't watch it or just slow down the speed of video!

[@taylordavison6849]

I went to the practical subnetting site and I did a subnetting problem of 95.203.49.222 /18. I thought the network ID was 95.203.49.192 but the correct answer was 95.203.0.0. Could somebody explain this to me? What did I miss?

[@taylordavison6849]

I've identified the first part of my misunderstanding. I tried to solve the equation as if the CIDR notation was above /24, which would've placed it in the 4th octet instead of the third. I still don't quite understand how the network ID is 95.203.0.0, so if anyone can explain, I'd greatly appreciate it.

[@taylordavison6849]

Okay. I think I have it all figured out. /18 has a group size of 64. The third octet is 49. The Network ID is the number before the target IP. Folks, never try to subnet when you're tired. You'll make embarrassing mistakes.

[@PracticalNetworking]

Taylor, I've enjoyed seeing this series of comments going from "I don't understand" to "I've figured it out". Well done! Figuring it out yourself will ensure you never make the same mistake twice. I applaud your effort. =)

[@user.netizen11]

@@taylordavison6849 Yes, that mask is a wife of an IP address. If any human tries to fit wrong wife next to an IP address then it gets real angry, and we end up apologizing to ourself because of our own stupidity.