I thought I understood subnetting until I discovered VLSM. Thank you for making this topic so simple while so many others complicate it beyond reason. I can begin practicing now!
He found the Magic number with a subnet mask of /22, which is 4. This means the octet we're in [octet-3] will increment by 4's, starting at 0. 172.29.0.0 /22 -- is the first Network Address. 172.29.4.0 /22 -- is the 2nd Network Address. 172.29.8.0 /22 -- is the 3rd Network Address. Now, once you know the 2nd Network Address (172.29.4.0), if you SUBTRACT 1 you'll get the Broadcast IP of the previous subnet. And Broadcast IPs are always the LAST IP in a subnet's range. So, 172.29.4.0 - 1 IP = 172.29.3.255. Now you know the span of the 1st subnet: 172.29.0.0 thru 3.255
Disregard...I found the answer below. 172.29.3.255 is the last usable address in a /22 network. Since he is only working within the address space in the 172.29.3.255 network we don't need to deal with the 172.29.4.0 and beyond addresses.
If you find the Magic number you'd see that it was a '4'. You'd also notice you were in Octet-3. This tells you to increment Octet-3, starting at 0, by multiples of 4. So, your Network addresses would look like this: xxx.xxx.0.0 xxx.xxx.4.0 xxx.xxx.8.0 and so on. Now, once you know the 2nd Network address, simply subtract 1 and you get the Broadcast IP of the previous range. In this case you'd get: xxx.xxx.4.0 - 1 = xxx.xxx.3.255
172.29.3.255 is the last usable address in a /22 network. Since he is only working within the address space in the 172.29.3.255 network we don't need to deal with the 172.29.4.0 and beyond addresses.
Sorry for the confusion, I say 256 host addresses generically, 254 are the usable host addresses. The network address and the broadcast address are not usable host addresses. It is just my manner of speaking and discussing the topic within my class and it carries over into the videos. You are correct in your understanding.
you video is very confusing...you are bringing the number on the video without giving reasons why those numbers are there as if we already know it. sir you know it we don't. so please don't irate us with your video
I thought I understood subnetting until I discovered VLSM. Thank you for making this topic so simple while so many others complicate it beyond reason. I can begin practicing now!
You're my favorite person ever - I've read and watched so many things to try to explain subnetting and this is the first one I understood!
Studying for my exam... I am so grateful you took the time to share this video. Thanks!
you saved me in 2019 ... cheers!
Thank you! This helped me out on a subnet project I was working on.
Thank You for a great tutorial. Watched also the " What is the subnet?Easy solution". Great teaching skills You got.
Thank you for the videos. Its been so helpful.
Great video, helped me with my networking homework!
Thank you very much, excellent explanation.
how did you compute your network endpoint so quickly. that step seemed to be a bit overlooked. maybe im just lost.
easy tutorial, easy understand, very nice
how did u come up with that range???
I have one question : Would I have time to make all this calculations on a piece of paper during the exam?
could you please tell me how did you came up with 172.29.3.255?
He found the Magic number with a subnet mask of /22, which is 4. This means the octet we're in [octet-3] will increment by 4's, starting at 0.
172.29.0.0 /22 -- is the first Network Address.
172.29.4.0 /22 -- is the 2nd Network Address.
172.29.8.0 /22 -- is the 3rd Network Address.
Now, once you know the 2nd Network Address (172.29.4.0), if you SUBTRACT 1 you'll get the Broadcast IP of the previous subnet. And Broadcast IPs are always the LAST IP in a subnet's range.
So, 172.29.4.0 - 1 IP = 172.29.3.255. Now you know the span of the 1st subnet: 172.29.0.0 thru 3.255
Thanks this helped alot!
i understand clearly , thanks :)
@2:59 video time stamp, where did the 3 come from? Anyone?
why did we have to pick /23 for the 1st one since at /22, it can fit over 260??
Good tutorial.
how did you come up with the network 172.29.0.0-172.29.3.255?
Did you ever find your answer to this question?
Disregard...I found the answer below. 172.29.3.255 is the last usable address in a /22 network. Since he is only working within the address space in the 172.29.3.255 network we don't need to deal with the 172.29.4.0 and beyond addresses.
how did you come up with 172.29.3.255 as the end of network space?
If you find the Magic number you'd see that it was a '4'. You'd also notice you were in Octet-3. This tells you to increment Octet-3, starting at 0, by multiples of 4. So, your Network addresses would look like this:
xxx.xxx.0.0
xxx.xxx.4.0
xxx.xxx.8.0 and so on.
Now, once you know the 2nd Network address, simply subtract 1 and you get the Broadcast IP of the previous range. In this case you'd get: xxx.xxx.4.0 - 1 = xxx.xxx.3.255
bthw thnx for the tutorial it was so helpfull
excause me can u tell me the name of the network diagram software u use pleasee...
Cisco's Packet Tracer app. It's free now...
What is the space if my subnet is 24?
wonderful!!!
Beautiful...
You said, that the magic number is 4, and when you placed the address, you put 172.29.3.255, what happens to the 4?
Andy
172.29.3.255 is the last usable address in a /22 network. Since he is only working within the address space in the 172.29.3.255 network we don't need to deal with the 172.29.4.0 and beyond addresses.
Andre M Correct!
what is the magic number when using /24 network?
+Singh Gurpreet The magic number on /24 is "1" the networks go up by one in the 3rd octet
Wait so the broadcast address and network address is defined as a host address?
Sorry for the confusion, I say 256 host addresses generically, 254 are the usable host addresses. The network address and the broadcast address are not usable host addresses. It is just my manner of speaking and discussing the topic within my class and it carries over into the videos. You are correct in your understanding.
I'm confused doesn't /24 give you 254 hosts since 0 and 1 is reserved for network and broadcast.
254 "usable" hosts
oh okay
Can someone say why he didn't take /25 CIDR here instead he went for /26?
1 year late reply but, its because the network was only looking for 60 and not a larger amount.
waw
The mask is the key. Always the mask. Remember... this is classless subnetting.
In fact, it's also VLSM [Variable-Length Subnet Masking]
2host/toast
you video is very confusing...you are bringing the number on the video without giving reasons why those numbers are there as if we already know it. sir you know it we don't. so please don't irate us with your video