IPv4 Subnetting - Counting subnets and usable hosts per subnet

[@claudem8579]

Over three years since you posted this video and you're still helping people! Thank you, thank you THANK YOU!!!!!!!

[@jfisher164]

Oh my god…this is how it should be explained in every course. Well done!!

[@alishariff3777]

By far one of the simplest explanation I have seen on this subject matter. God Bless you Sir. Thanks

[@Robertlavigne1]

Thanks. I getting really frustrated because I wasn't using the class system and couldn't figure out why the "great divide" kept shifting around in practice problems. Your 4 steps really cleared it up for me.

[@4Y0P]

This helped me out so much, very clear! Big props for explaining it in a simple way

[@billyhill1320]

Thanks for this video, you explained a complex issue in such a clear and easy to understand way.

[@PatrickHornung]

You're very welcome!

[@theimprovist4158]

Beautiful explained, thanks a ton!

[@waynestevenson7833]

Very clear and concise explanation...thanks.

[@mahammedhagi98]

THANK YOU SO MUCH. YOU DID BETTER THAN MY PROFESSOR.

[@elfstone8606]

Yes thank you for this. I'm in my first networking class and really don't enjoy this stuff but your video was super helpful!

[@nashaatmena7687]

thx for your simplicity for explaining the subnetting. thx for your valuable information video

[@ZoeBredan]

you are simply amazing ..... im here in the middle of the night studying this, you made it so easy...although i dont have the real answer i came for which is getting the ip address range ....i can search it out....thanks so much

[@celltech1934]

Great job, you are good at teaching

[@TheBlueMahoe]

Patrick this is very thorough and tidy. I am preparing for CCENT 100-105. do you have videos and practice questions on additional topics for the syllabus

[@KyserMontalvoC]

Great video! Could you explain why we are using classes? I am confused because I thought the C in CIDR meant classless which means we shouldn't be using classes

[@neeldsouza7170]

Thanks!! This helped me out so much, very clear

[@azoozalshbibi9410]

You are professionals✨

[@ammongaffney4711]

Thank you Thank you!!!!!!!!!! you made it finally make sense.

[@worldwondering2433]

Great video Thanks a lot sir

[@Boost_95]

This video helped a lot. Thanks!

[@stevenfeinberg6053]

Very good video

[@lumizoidtech3193]

Please don't laugh. I find your videos to be very helpful in my studies right now. When you say 16-2 = 14 hosts, is that 14 hosts total for all the 16 subnets, or is that 14 hosts per subnet. If the latter, is that 14 x 16 (subnets) = 224 total hosts then?? Thanks for clarifying. Great videos! I have sub to you.

[@PatrickHornung]

14 hosts in each subnet. So, 14 hosts in the first one, 14 in the second, etc., all the way to 14 hosts in the 16th subnet.

[@lumizoidtech3193]

Thank you, sir!

[@shihabahmed754]

if the great divide and subdivide fall at same point then how to calculate the hosts and subnets? For ex: 211.17.180.0/24

[@PatrickHornung]

Same way. With /24, there are 24 bits on the networking portion and 8 bits on the host portion. There would be *no subnets*, since it is not a subnetted address range. It is a classful C range. However, you could count by the powers of two to calculate hosts: 2, 4, 8, 16, 32, 64, 128, 256. So 256 addresses, but with hosts we always must remove two hosts as the 'bookends' of the network (network ID and broadcast). So the number of usable hosts is 256-2, which equals 254.

[@fraser2630]

How do I calculate subnet for 8 usable hosts 192.168.10.0 /24

[@AnfecsIan]

It would be the same like in the video, because if you want 8 usable hosts then you need 4 subnet and host bits. It's a 24 CID so the first 3 octets don't change. So 14 hosts and 16 subnets with the address you provided.

[@NextGenWarfare]

Doesn't Class A Range from 1 - 126? 127 is reserved to for loopback hence it is outside of the range. Other than that good video.

[@PatrickHornung]

Practically and usably, yes - class A usable addresses go from 1-126. But based on binary, the divide is based on the first bit. 127 is technically a class A range, because the entire 127 range is in the same network. If 127 were class B, then only 127.0.x.x would be loopback, which it is not.

[@azoozalshbibi9410]

American Military Forum : but is still in class A

[@Lashan_]

THANK YOU!

[@PatrickHornung]

You're welcome!

[@c-k4746]

thank you so much

[@hasnishahaidi6358]

Assalamualaikum hi, tysm Sir🌟 God bless u always🕊 now🥰 i understand

[@PatrickHornung]

Glad to hear that!

[@joepeeer4830]

awesome

[@saurabhsinha8913]

please calculate subnets and hosts per subnet for 192.168.120.193/25? also all addresses not only count

[@reynaldoalvarez9370]

very helpful!

[@Techtips_AU]

Please explain this : /26- Subnet mask 255.255.255.192 No. of subnets : 262144 (262142) No. of hosts- 62 The host part is clear as per your explanation but number of subnets is not clear plz reply :( Thanks in advance.....

[@PatrickHornung]

Sounds like you were starting from a Class 8 address (/8, or 255.255.255.0) and going down to a /26. That means you've borrowed 18 bits to get there (26-8). You've gone from 255.0.0.0 to 255.255.255.192. Or in binary: 11111111.00000000.00000000.00000000 to 11111111.11111111.11111111.11000000. Notice the 8 ones in the first binary number, and the 26 ones in the second binary number. The zeroes that turned to ones represent the subnets created. (11111111.SSSSSSSS.SSSSSSSS.SS000000, where S is a subnet bit) 2^18 is 262144. There will be 262144 subnets when you borrow 18 bits. You don't have to subtract two from that number, since it is subnets. We only need to take two away from the hosts value because of the broadcast and network ID. Hope this helps!!

[@arabiclive007]

A class B network on the internet has a subnet mask of 255.255.240.0. What is the maximum number of hosts per subnet ? can any one please help me ...??

[@eazy8399]

4094

[@inkbythebarrelandpaperbyth6905]

thank you so much!!!!!!

[@liamvg]

Why isn't it just 192.168.92.0 = 255-2 (253), then 192.168.93.0 another 253, then 192.158.94 and another 253 and on and on?

[@raghavendramcag]

if i need 1000 ip address, using class A how to calculating 1000 ip address

[@arthurwatts1680]

OK, OK - we're not *starting* with a /28 CIDR and subnetting, *we're just asking how many hosts and subnets we can cram into that space using /28* - suddently the example makes sense. Incrementing by 16, these are our networks for /28: *Network#1 192.168.92.0 (useable hosts 192.168.92.1-192.168.92.14, broadcast 192.168.92.15)* Network#2 192.168.92.16 Network#3 192.168.92.32 Network#4 192.168.92.64 Network#5 192.168.92.80 Network#6 192.168.92.96 Network#7 192.168.92.112 Network#8 192.168.92.128 Network#9 192.168.92.144 Network#10 192.168.92.160 Network#11 192.168.92.176 Network#12 192.168.92.192 Network#13 192.168.92.208 Network#14 192.168.92.224 Network#15 192.168.92.240 (1-15 totals 16 networks, each with 14 usable hosts, using a mask of 255.255.255.240 (our CIDR 28)) Once you have the increment, the rest is simple arithmetic - you know you have to add 15 for the broadcast and the usable hosts are everything in the middle - I hope I havent confused anyone any more than they may already be, but typing it out for myself helped me understand what was going on here. Thanks for the vid.

[@OriginalVomitPig]

Thank you for this.

[@joepoor5327]

awesome