Subnetting Cisco CCNA -Part 4 The Magic Number

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  • Опубліковано 24 гру 2024

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  • @JustSimpleInfo1
    @JustSimpleInfo1 11 років тому +2

    I am taking a Cisco Class at my local Community college, and this video helped me have my "Ah HA!" Moment. Everybody teaches different, but this video series, is what helped me. Thank you, I will be sharing it with my fellow classmates.

  • @wakaflaka6710
    @wakaflaka6710 11 років тому

    It's like you get it in the first vid!! It's just naturally clicks! Then the other vidz are like supplements that show different ways to "get it". Good stuff dude.
    Innovative teaching. I took this class 10 yrs ago and dropped it cuz of mundane teaching methods. Thanx for your methods.

  • @MelodicAxe
    @MelodicAxe 10 років тому +29

    passed my ccna on the 14th of June 2014 because of this video thanks!!!!!

    • @MelodicAxe
      @MelodicAxe 9 років тому +1

      Almost the entire exam relies on you knowing how to subnet. I would say 90%. I'm now looking to book my ccnp routing and switching, switch exam.

    • @MelodicAxe
      @MelodicAxe 9 років тому

      Volf Khat but when I say subnetting was a huge chunk of the exam its not just simply asking to find host numbers or broadcast addresses it's all interconnected with topics like acls natting and some routing. And yes I have done 2 part exam.
      The book that I would recommend is ccna by todd lammle.

  • @dhoest728
    @dhoest728 14 років тому +1

    Wow, man I am taking the Cisco courses now. I already took the first one, and now am taking the second class, routing protocols and concepts. The subnetting was always somewhat difficult to understand but that magic number is THE SHIT!! That was VERY easy to understand the way you explained it, great job man. Im going to check out some of your other vids.

  • @CarlosElPeruacho
    @CarlosElPeruacho 11 років тому +37

    Just to clarify for the people who did not get why he used /25 instead of /24, /24 consists of only 1 network with 254 usable hosts, this configuration required 2 networks, with at least 123 usable hosts, due to the Teachers Network requirement. Using /24 would allow the users but not the separate networks therefore we would use /25.

    • @CandleKern
      @CandleKern 7 років тому +1

      thank you!!

    • @ismailaibrahim5439
      @ismailaibrahim5439 7 років тому

      Good explanation

    • @CULTUREABOY
      @CULTUREABOY 5 років тому +2

      Thanks for the explanation, i was racking my brain trying to figure out why it wasn't. /24

    • @abovethehorizon2023
      @abovethehorizon2023 5 років тому

      Thanks a lot.

    • @LukeSkywalker-ig3mc
      @LukeSkywalker-ig3mc 5 років тому +4

      Thanks. So 128 would be the Network ID with 2 separate networks. Confused me because 44 users plus 123 users = 167 users/hosts. 128 host isn't enough computers for the users but since 128 per network. 0-128, network ID 0 and 127 broadcast, 128 network and 255 broadcast ID. Meaning 129-254 for second network for teach network IP addresses for the last octet!

  • @DarkArtStyle
    @DarkArtStyle 7 років тому +1

    I'm very grateful to your tutorial so far sir, the tutorials had taught me better than they did teach at school

  • @VenomOFwAR99
    @VenomOFwAR99 12 років тому

    @danscourses u explain this better than my Cisco instructor! i was confused for a month on subnetting and i watch ur video and i did a *face* *palm* *head* *desk* reaction because it is simple!! lol thanks for the video :)

  • @notomab3
    @notomab3 13 років тому

    Hey i just wanted to thank you, This was really good, my college professor couldn't teach this very well . The magic number is a great concept.

  • @Lobo_Loco1
    @Lobo_Loco1 10 років тому +1

    Thanks very much for making this video, I'm just starting to do CCNA and I'm kind of struggling with it but these videos are giving me more and more insight, love the magic number bit, got that down to a regular, overall I think I just need to keep reviewing and keep going over the material. Big help thanks again bud!

  • @RickMomterrosa
    @RickMomterrosa 12 років тому

    Man this has to be the best explanation i have ever heard in my life great job ..

  • @danscourses
    @danscourses  14 років тому

    @benghaith 127.0.0.1 is your loopback address it is your own NIC. You can ping 127.0.0.1 to see if IPv4 is installed and bound to your NIC. It is Localhost

  • @danscourses
    @danscourses  14 років тому +3

    @surlagachette2 Yes that is correct, 32 host addresses but only 30 are usable.

  • @r0ck3tstar
    @r0ck3tstar 15 років тому

    THANK YOU SOOOO MUCH!! I've been trying to get subnetting for the last 4 days and you have made it so easy for me.. Thank You!

  • @GreenScreenEvents
    @GreenScreenEvents 12 років тому

    Thank you Dan for the video. It's very easy to follow your teaching style.

  • @danscourses
    @danscourses  15 років тому

    I was just trying to show that when you subnet a network address you dikvide it into smaller networks. If your goal is two subnetworks, and the most users you will need is 123 then you can divide it into 2 subnetworks of 128 hosts each. It is a hypothetical situation but useful in passing the Cisco CCNA exam

  • @shows01
    @shows01 11 років тому +1

    love the videos, I have been trying for the past week to learn this stuff.

  • @danscourses
    @danscourses  12 років тому +2

    Yes the magic number still tells you where the networks are (how the networks increment) even if the subnet mask is less than /24. if the subnet mask is greater than /24 the magic number also equals the number of hosts in the network

  • @danscourses
    @danscourses  12 років тому

    thanks for the feedback, I am glad it helped out.

  • @netnut-sx1hq
    @netnut-sx1hq 10 місяців тому

    You sir have blown my mind. Thank you so much.

  • @4kcss
    @4kcss 11 років тому

    Great subnetting tutorial! Helped me understand the magic number trick well. Thanks so much

  • @TROOP3RAK47
    @TROOP3RAK47 7 років тому

    Thank you Sir!
    May you have all the success for your present and future endeavors...

  • @nelehyhprum
    @nelehyhprum 12 років тому

    Thank you, clearest explanation I've ever had on this subject...

  • @danscourses
    @danscourses  11 років тому

    Yes those are intended to be two different sized subnets. Students in one subnet, admins in another.

  • @danscourses
    @danscourses  13 років тому

    It is all based on the binary. the only way to understand IPv4 subnets is to know how binary works. Go to my CCNA1 playlist on my youtube channel and I cover the whole process.

  • @May16Joe
    @May16Joe 12 років тому

    Thank you for your videos, you helped me out so much clarifying my questions.

  • @Lucad2278
    @Lucad2278 2 роки тому

    At 3:35 - how is 159 a usable host address? I thought the broadcast address is reserves therefore not usable as a host address?

  • @cashregistergrl
    @cashregistergrl 8 років тому

    :)I really love this video. I forgot about the magic number trick and this tutorial refreshed my memory in a matter of minutes!! Thank you:)

  • @stevelong3249
    @stevelong3249 9 років тому +1

    I like how you present the material other than I would like it if you planned your examples ahead of time. That way it would be easier for me to follow with less restructuring of your examples. It did get a little crazy in several spots. Overall I really liked it. Thanks for taking the your time to create these.

  • @diverron
    @diverron 15 років тому

    This is really great work..
    Could you show one where you are just given a class B address with no netmask and were asked to create 4 subnets(or more) with different numbers of hosts on each subnet?

  • @poikafin1
    @poikafin1 11 років тому

    Dan..thanks for the info? Is the number of hosts NOT equal to the 0? eg 255.255.255.240 has MN =16 a

  • @xash3x
    @xash3x 12 років тому

    your very great in teaching, it make's so easy to understand subnetting. thank you so much sir. xD.

  • @herbsmoney5861
    @herbsmoney5861 8 років тому +6

    You are the best subnet teaher

    • @borgy78
      @borgy78 8 років тому

      Yes i learned a lot.

  • @vJosipovic
    @vJosipovic 14 років тому

    This was very helpful!!,thank you so much for these tutorials,all the best! :)

  • @killerpeaks
    @killerpeaks 11 років тому

    At the end of the video you choose /25 because it allows for 126 hosts. Do you choose this because it allows for the 123 teachers and the 44 admin. I was thinking that I would add the students and the admin for a total of 167 host, which would lead me to choose /24. Are you asking what do you need to choose for 123 teachers as well as what do you need to choose for 44 admin?

  • @miko-rv8sl
    @miko-rv8sl 9 років тому

    Good trick! Easy to understand, learned a lot! Thanks!!

  • @volante8657
    @volante8657 12 років тому

    does magic number works with anything less than /24? like if I have a subnet mask of /18, is this still applicable to my network? many thanks!!

  • @volante8657
    @volante8657 12 років тому

    but i am struggling for that, is it 255*subnet bit at the previous octet?

  • @Fyazzayf
    @Fyazzayf 8 років тому +26

    hey bro, actually its not 32 hosts... its only 30 hosts because one of them is network number and the other one is broadcast number. so u will be having only 30 hosts for every network increment.

    • @Myzz617bean
      @Myzz617bean 8 років тому

      I agree. I learned this awhile ago and time to brush up! But when doing notes it was messing with me because I recall the broadcast and network address are not useable IP's for hosts. Very important which is what i feel like is the only thing left out

    • @NWWalkerMusic
      @NWWalkerMusic 8 років тому +3

      At 7:40 into the video he makes the distinction between "hosts" and "usable hosts". I agree with you in how he mislabels the number of hosts, but wanted to let you know that he does clarify this issue later on.

    • @joshandres4964
      @joshandres4964 8 років тому

      Yeah and technically if you are subnetting, when you are anding, that the first network since its /27. if it was /24 then yes he would have that many networks

    • @jcbiglangawa
      @jcbiglangawa 4 роки тому +1

      He is right there is 32 hosts.. This is how it goes "there's 32 hosts and 30 of them are usable hosts" Hope this helps.

  • @reaction4me
    @reaction4me 10 років тому +5

    there are 30 hosts per network, you save two of the hosts 1- for network 1- for broadcast

    • @molb78
      @molb78 9 років тому

      +reaction4me not really? 0 network adress, 255 broadcast. He says within the subnet you can use the "broadcast" adress!

  • @enyawix
    @enyawix 11 років тому

    end is a bit confusing are you using vlsm?

  • @joed960
    @joed960 11 років тому

    thanks for the vids my friend it helps a lot but small humble tip use "Ctrl+[" or "Ctrl+]" to control font size

  • @traviswilson2098
    @traviswilson2098 9 років тому

    Thank you very much this helps a lot better than my professor did.

  • @ak_naral
    @ak_naral 7 років тому

    8:24 he says, "Next Movie". So true. Very entertaining.

  • @paulendjatsana
    @paulendjatsana 3 роки тому

    Please how did you came about with 159?

  • @michealking61
    @michealking61 8 років тому

    If 128 is the network and 159 is the broadcast how can you get 30 usable hosts? 129 + 30 gives you 159 but that the broadcast address?

  • @danumber2
    @danumber2 6 років тому

    I could never understand subnetting until I saw these videos. Thank you so much!!! Do you have any courses for CCNET 100-105 and 200-205? If you do I will sign up. I really enjoy your teaching ways.

    • @danscourses
      @danscourses  6 років тому

      That's great to hear Carlos. I will be teaching a full CCNA series of courses this Fall (registration begins Sept 5th) "online" through Central Oregon Community College (www.cocc.edu)

    • @danscourses
      @danscourses  6 років тому

      cocc.edu (CIS-151C Fall Quarter)

    • @danumber2
      @danumber2 6 років тому

      Cool. Now I have done online classes and they are good but usually the instructor just goes over the book material and leaves us alone to do labs. I can do that by myself. How do you teach? Is it like the videos that you do hands on labs etc?

  • @timeless909
    @timeless909 11 років тому

    thank you so much for this video. it's been bothering me what the /8 /24 slash whatever. This video solved my question. You've got a new subscriber! =) By far you're videos are easiest to understand.

  • @bestviral3808
    @bestviral3808 5 років тому

    It makes me very clear now Thank you so much

  • @kwanzanator
    @kwanzanator 11 років тому

    I am thinking the same thing. Why choose /25?

  • @lifeanew5530
    @lifeanew5530 8 років тому

    if the teacher network requires only 44 hosts on a separate network wouldn't be /26 good enough?

  • @chessie459
    @chessie459 13 років тому

    @danscourses yeah i get it, count the zero bits minus the network devices. thanks again! :D

  • @ramirez368
    @ramirez368 10 років тому +1

    In this example at the end....shouldn't be the total of both network...? 44 users+123 users to calculate the total host for both networks....? total users 167?

    • @reaction4me
      @reaction4me 10 років тому +3

      no, there are two separate networks, each needs there own network so they dont share info

  • @sachintharashmika969
    @sachintharashmika969 4 роки тому

    brother it must be
    Host's : 32-2 : 30 Right?
    sorry if wrong! , but according to what i learned
    hosts : its (2ⁿ - 2) Right?

    • @danscourses
      @danscourses  4 роки тому

      Correct

    • @danscourses
      @danscourses  4 роки тому

      If there is an error in the video I tried to point it out on annotations but UA-cam got rid of the Annotations that floated on top of the videos. Probably because Flash was used earlier

  • @purelaffs
    @purelaffs 5 років тому

    why is 159 the broadcast address?

  • @chottokawaii
    @chottokawaii 7 років тому

    dumb question, so the MN means the usable hosts?

    • @danscourses
      @danscourses  7 років тому

      It means the binary place value of the last 1 in the subnet mask (read from left to right). It tells you what the networks area, starting at 0 ( in the octet of the last 1) and going up by the magic number.

    • @danscourses
      @danscourses  7 років тому

      If the MN happens to be in the 4th octet, it will tell you the number of hosts in the subnet. Subtract 2 to get the usable hosts. The number zeros in the subnet mask is a better way to tell how many hosts are in the subnet. 4 zeros or 2 to the 4th power equals 16 hosts, minus 2 is 14 usable hosts

    • @chottokawaii
      @chottokawaii 7 років тому

      danscourses so in this tutorial, your MN is 32. means there are 5zeros left. so, its 2 to the fifth = 32 - 2 = 30 usable hosts?
      am i getting it right? im really dumb. its been 2days that I keep watching your vids to get it. i appreciate the reply. thanks!

    • @danscourses
      @danscourses  7 років тому

      If the subnet mask is 255.255.255.224 or /27, then it is correct, because there would be 5 zeros left. and 32-2 = 30 usable hosts!

    • @chottokawaii
      @chottokawaii 7 років тому

      danscourses oh cool! thanks, Sir! I'm learning a lot from your vids. Thank you!

  • @simakarmakar438
    @simakarmakar438 7 років тому

    what will be the magic number when CIDR 8 or 16 0r 24 ????

  • @chessie459
    @chessie459 13 років тому

    how would you know the number of hosts in a subnet? how would you know that there are 255 hosts in /24? 128 hosts on /25?

  • @vijayalaxmishiraguppi9807
    @vijayalaxmishiraguppi9807 4 роки тому

    Sir why you have used there 24 because I am a a biginner so please reply me

  • @joedarvish70
    @joedarvish70 9 років тому +1

    Here you have 167 users and if each user is one host, why do you chose 128 hosts?

    • @SmilesNA
      @SmilesNA 8 років тому +1

      Because you can have 2 sub networks with this. 1 for Admins 1 for Teachers

  • @asgSKUMMY
    @asgSKUMMY 10 років тому

    Great. Thank you soo much! Finally got it!

  • @natbett206
    @natbett206 5 років тому

    You should lecture! My lecturers did a real bad job explaining this! Thank you!!!!

  • @soultakersys
    @soultakersys 12 років тому

    I was about to write the same, u should check that out, anyways, great Video! great help for students, greetings from Chile

  • @annkky
    @annkky 4 роки тому

    Pls solve for 172.18 208.224/22 what's first valid network address?

  • @alvaromoreira2375
    @alvaromoreira2375 11 років тому

    Great Method!!! Thanks Man!

  • @APPOLO30
    @APPOLO30 7 років тому

    Thank you sir you made subneting easy

    • @danscourses
      @danscourses  7 років тому

      My pleasure, thanks for the feedback!

  • @splashasc
    @splashasc 10 років тому +1

    0-127, 128-256.... two networks 126 usable per network

  • @arjay2002ph
    @arjay2002ph 13 років тому

    so if i'm correct the xxx.xxx.xxx.0 - will always be the 1st network regardless of their class?
    noob here

  • @batsin9045
    @batsin9045 4 роки тому

    Confused how 126 usable hosts cover 167 total users..?

  • @jerrydixon9343
    @jerrydixon9343 5 років тому

    10 years and no one pointed out that a /24 actually has 256 hosts, 254 usable? Or did I miss something?

  • @ramirez368
    @ramirez368 10 років тому

    Yes Dan I see.....you are correct, thanks again!!!!

  • @sizwemkhonzasizwe_mkhonza
    @sizwemkhonzasizwe_mkhonza 12 років тому

    wow.thanks for the lesson

  • @schioncalzanzi1091
    @schioncalzanzi1091 6 років тому

    Good job though you could have done better, instead of using admin which is a broad approach in determining who is who- you should have used teachers vs students - it makes much more practical in real life situations or scenarios. The overall lesson is awesome period of instruction. I am working on my CCIE. Thanks for the refresher.

  • @rius3044
    @rius3044 Рік тому

    🔥🔥🔥

  • @gamalmothersil6943
    @gamalmothersil6943 7 років тому

    Good explanation but all your example are above 24, what if the (/) number is below 24. Example /22

  • @reesepa4
    @reesepa4 11 років тому

    I don't get it! You have a total of 167 users! So shouldn't it be /24 instead of your answer of /25 for 126 usable host!

  • @Jamerican284
    @Jamerican284 6 років тому

    I think that you are calculating the host section incorrectly. For example, a /27 would be 30 usable host addresses 2x2x2x2x2=32-2 and this is how I know it to be in any language or place.

  • @TeatroSG
    @TeatroSG 10 років тому

    thank you so very much!

  • @oceanman20000
    @oceanman20000 11 років тому

    256 - Sunbnet = Magic No
    256 - 224 = 64 - 2 = 62
    the 2's are the Network and Broadcast which will not use in future

  • @abdullahmuhammad2010
    @abdullahmuhammad2010 9 років тому

    for admin and teacher to be two different networks the correct answer would be /26

  • @Altawer
    @Altawer 6 років тому

    thank you brother

  • @WAsucksblackducks
    @WAsucksblackducks 6 років тому +1

    It should be "/24 256 hosts with 254 usable hosts", "/26 64 hosts with 62 usable hosts", "/27 32 hosts with 30 usable hosts".

  • @techchamp1
    @techchamp1 11 років тому +1

    attention to detail please!!!!

  • @ViciousXUSMC
    @ViciousXUSMC 10 років тому +2

    /24 256 hosts - 2 for broadcast and network = 254
    your /25 @ 128 is correct so /24 should be *2 aka 256

    • @tecx9948
      @tecx9948 6 років тому

      this is what i was thinking exactly

  • @HadziTonich
    @HadziTonich 8 років тому +1

    Excuse me, but, I think that u r making a mistake here... and in the other videos before this one, when it comes to host's number ? [Host number = ((2)^(host bits)-2)] ? So in this case, there are 233 hosts for the /24, 126 host's for the /25, 62 hosts for the /26...etc.... Anyway, grate tutorials !

  • @GautamThakur
    @GautamThakur 12 років тому

    thanks man

  • @SoCalGuy93065
    @SoCalGuy93065 9 років тому +1

    You'd think that you'd have figured out that you need to use a smaller font the first time.

    • @richbrazzel2245
      @richbrazzel2245 9 років тому +4

      +SoCalGuy93065 Really? After all the effort, time and attention Dan has put forth in creating ALL these videos for those of us who DON"T know everything, THAT"S what you have to bitch about? The font? What a schmuck.

  • @ukella
    @ukella 11 років тому

    agreed, at least the discussion at the end is pretty confusing.

  • @alex08585
    @alex08585 10 років тому

    8 Networks/subnets refer to 2^3=8[Total number of Networks]
    Isnt the Usable number of Subnets 2^3 - 2 = 6 [Usable Number of Networks/SubNets]

    • @sarahchua2811
      @sarahchua2811 5 років тому

      john doe just saw your comment but I think you are counting 1s that’s stand for network you should count on 0s of we are talking about hosts cause 1 represent network and 0 represent hosts so in this case it should be 2^5-2 😊

  • @TheXtreme13X
    @TheXtreme13X 6 років тому

    No hosts 2 to 5th -2 30 hosts per network

  • @jannerelroche2482
    @jannerelroche2482 5 років тому

    set your font to smaller size first it is very annoying to watch you changing the font and moving things around it's an eyesore. We can see the text that would fit the screen no need to enlarge them! jeez but thanks for the video it helps

  • @techchamp1
    @techchamp1 11 років тому

    not 255 hosts, but 254 usable hosts, not 128 hosts, but 126 usable hosts

  • @rickboyd8676
    @rickboyd8676 10 років тому

    Not sure what he means when he says the networks go up by 32
    You know 0 32 64 96

  • @CrystalzEyeZ
    @CrystalzEyeZ 8 років тому

    /24 = 255 hosts is Wrong........should be /24 = 256 hosts..

  • @TheXtreme13X
    @TheXtreme13X 6 років тому

    again /25 -2 126 hosts.

  • @GearHeads09
    @GearHeads09 8 років тому +9

    we have 30 hosts, dont make mistakes like this!!!!!!!!!!!! put annotations so the beginners know the right answer... !!! pffff

  • @athisipaka5499
    @athisipaka5499 5 років тому

    30 hosts

  • @nadeemnisar8476
    @nadeemnisar8476 7 років тому

    Slooooooow and mistakes. you wanna try again.

  • @tomislav3570
    @tomislav3570 11 років тому

    /24 has 256 host and 254 usable host , Usable hots are from 192.168.1.1 to 192.168.1.254 ! Broadcast: adress is 192.168.1.255.

  • @mossbens1005
    @mossbens1005 5 років тому

    too slow and frustrating to follow, typing, thinking, explaining same time with poor audio sync.

  • @danscourses
    @danscourses  11 років тому

    Yes those are intended to be two different sized subnets. Students in one subnet, admins in another.